The Great Flood of 1606

Relates to Philosophy and Science

I am going to start off this year's blogging by taking a philosophical approach to a controversial subject, and I apologise in advance if this is too close to any reader's personal experience, since it does relate in part to the recent events in Asia.

Yesterday, an article was published in the Times with the following sub-heading:

An Atlantic tsunami created our greatest environmental disaster, and it could happen again Michael Disney, Professor of Astronomy, Cardiff University. Published in The Times, January 4th 2005

In brief the article discusses accounts of a great flood occurring in 1607 in the region of the Bristol Channel and particularly Cardiff. The principle source for these accounts being a single pamphlet printed in London. I believe this article to be propounding an erroneous deduction lacking in objective (in the historiographical sense) historical evidence and influenced by temporal and personal biases that only hermeneutics could elucidate for future historians.

Of course, it is the privilege (even the obligation) of journalism to co-erce the facts to accommodate the author's own subjective conclusions. But an article, authored by a member of the academia, which Michael Disney represents, could easily fit into Carr's definition of historical facts because

It is never really a matter of the facts per se but the weight, position, combination and significance they carry,?, that is at issue. E H Carr, What is History: The George Macaulay Trevelyan lectures

Early in the article Disney states -

COULD a huge wave swamp Britain? Almost certainly. Historical evidence suggests that it has happened in the past.


No one can be absolutely certain that it was a tsunami, but the conditions suggest so. The sky was blue, the tide was high, there is a secondhand report of an earth tremor felt earlier that morning. It all fits together.

From my brief studies of Earth Sciences, I never recall either blue sky or a high tide being necessary conditions for a tsunami. While, positivism would almost certainly reject the final remark for lack of historical authenticity.

Historical evidence actually suggests that the Great Flood occurred on January 20th 1606, not 1607, and the cause of this event was the coincidence of meteorological extremes and tidal peaks.

A primary source for the Great Flood was written by John Paul, the Vicar of Almondsbury on 26th January 1606, which I will recount here in part (in its original language to avoid bias in interpretation):

But the yeere 1606, the fourth of K (King) James, the ryver of Severn rose upon a sodeyn Tuesday mornyng the 20 of January beyng the full pryme day and hyghest tyde after the change of the moone by reason of a myghty strong western wynd. So that from Mynhead to Slymbryge the lowe groundes alongst the ryver Severne were that tuornyng tyde overflowen, and in Saltmarsh many howses overthrowne, sundry Chrystyans drowned, hundreds of rudder cattell and horses peryshed, and thowsandes of sheep and lambs lost. Unspeakable was the spoyle and losse on both sydes the ryver.
The salt water was in Rednyng in Sansoms new chamber to the upper stepp save twoo, and in Hobbes house syx foote hyghe. In Ellenhurst at Wades howse the sea rose neere 7 foote and in some howses there yt ran yn at one wyndow and out at an other.
[..snip..] Also in Brysto by credyble report that mornyng tyde was hygher than that Evenyng tyde by nyne foote of water. John Paul, Vicar of Almondsbury, 26th January 1606

Another account exists in the parish memorandums of Arlingham, a village on the eastern bank of the arc of the Severn horseshoe bend 50 miles upstream from Cardiff. As mentioned in Disney's article, churches spanning the Bristol Channel coastline do preserve the memories of the Great Flood through plaques of commemoration demonstrating the extreme water marks attained in the great flood of 1606.

Yet there are occassional, but not primary, references that do support the backbone of facts for a 1607 flood. So could there have actually been great floods in consecutive years on the same day? Maybe, but references to the flooding of the River Taff in 1607 might suggest that a flood of 1607 could have been the result of freshwater flooding not saltwater inundation. While other non-primary accounts further support a flood inundation on January 20th 1607.

So where does this confused bundle of sources leave the actual history of the Great Flood? I cannot deny that the assertions I make here are influenced by personal factors contrary to historical objectivity - my own personal fascination with all things tidal - but the facts appear to be as follows:

  1. Primary evidence attains to a great flood occurring on January 20th 1606
  2. This flood conincided with the high tide
  3. This flood also coincided with syzygy, when the variation in high tide is at its peak.
  4. This flood conincided with strong winds in the west/south-west quadrant.

These conditions in combination would suggest the Great Flood was caused by an exceptional bore tide in combination with a storm surge as seen in the English East Coast floods of 1953 - there is no evidence for a tsunami!

With a brief venture into hermeneutic method I suggest that, perhaps, the 1607 pamphlet, entitled God's warning to the people of England by the great overflowing of the waters or floods, could have in fact been fervour inducing religious propaganda drawing on evidence from the parishes around the Bristol Channel recounting the flood of the previous year, itself becoming a source for further accounts of the misnomer that is the 1607 flood. It would not be the first time that facts have been mysteriously hyperbolized in the cross country journey from the West country to the capital - but I will not digress further now. Even to the present day local rivermen refer to the Severn bore tide as the flood tide - the Great Flood. Of course this is as much unsolicited conjecture as Disney's hypothesizing of a historical tsunami. [Updated] Discussion in the comments below has provided consensus that the 1606 and 1607 dates reference the same date/event in different calender systems.

The real crux of this rant is that we should not let current events interfere with our judgement and interpretation of historical data in a way that history itself overtime becomes remoulded to meet our own requirements with total disregard for the objectivity of historical facts.

Posted on Thursday, Jan 06, 2005 at 02:33:03.

Comments on The Great Flood of 1606 (21)

α comment

This is a very impressive blog with an abundance of primary source material- congratulations for putting it together so quickly. Apart from the impressive original account of the tidal flood, which TW points out includes the two vital elements of powerful winds from the west and top spring tide,which combined to produce a storm surge of epic proportions, culminating in a phenomenol bore tide and Flood, the parish references from Arlingham church are quite astonishing. Reference to the Ordnance Survey sheet OL14 shows the church at Arlingham to be above the 10metre mark above mean sea level. The farm buildings including the rectory barn are just below the 10metre contour. The reference to the overturning of an oar boat in 1644 by the bore waves and the ensuing drowning of 5 soldiers also makes graphic reading. The vicar's comments suggest the early decades of the 17th century was a period of flood tides far beyond anything of our modern times. All of which adds credence to the extraordinary myth of the river Severn and the Bore which first appears in print in Nennius' History of Britain, collated by Nennius in the early years of post 800AD.

Posted by donny
Thursday, Jan 06, 2005 at 19:00:58

β comment

I hope you remembered to draw a breath before finishing your comment D :)

For once Google actually came up trumps with the Arlingham record which I hadn't read before. It is another account that could confuse dates with the 1606-7 date reference, but the quote in the second paragraph clearly indicates the year of the flood referred to is 1606:

The somer following [ed. the flood] there was a most extreame hott somer, in so much that many died with heat; and in 1607 was a wonderful frost;

Although I only mentioned it indirectly above with reference to the location of Arlingham, any tsunami related to the Great Flood must have been extremely dexterous to have negotiated the horseshoe's southern arm prior to flooding Arlingham ;))

Posted by Tom
Friday, Jan 07, 2005 at 00:03:28

γ comment

The 4th Regnal year of King James was 1606/7, which doesn't mean that it spread over two years but rather that it reflects the different dating convention before calendar reform in 1752. In 1606/7, the legal year began on March 25th. This means that December 1606 was followed by January 1606, and 1607 didn't start until the end of March. However, there also existed the idea of a christian year starting on January 1st (anno domini) rather than the legal year, so some records may refer to the 'legal' January 1606 as January 1607. Causes confusion in my hobby, which is genealogy, and may also explain the apparent different dates in the Cardiff Tsunami reports. As a Caardiff lad, I likes the sound of a Caardiff 'Sunaami, but those tidemarks in the churches on the Gwent levels are indeed a sobering sight! Incidentally, one part of the UK steadfastly refused to have anything to do with calendar reform - the Inland Revenue. They even ignored the 10 day adjustment necessary in 1752 to bring us in line with the rest of Europe, which is why the tax year end is still 5th April!

Posted by Michael
Saturday, Jan 08, 2005 at 17:03:16

δ comment

Thanks for that Martin, a very illuminating comment. Certainly helps explain the year discrepancies, potentially juxtaposing the varied accounts into a single phenomenal event.

Posted by Tom
Saturday, Jan 08, 2005 at 18:03:16

ε comment

Fascinating discussion. Personally, I still think a tsunami more likely as the cause of the 1606 or 1607 flood, mainly because it apears the flood peak was so much higher than normal high tide or high spring tide. A high spring tide, with waves driven by strong winds, could well have been enough to damage flood defences and inundate low-lying areas, but would not explain a water level three metres above normal high tide. Storm surge caused by low atmospheric pressure could only have slightly increased the water level. If the sky really was blue then air pressure is unlikely to have been particularly low and therefore storm surge unlikely to have been significant. Additionally, the flood is reported to have occurred along both sides of the Bristol Channel at least as far west as Carmarthenshire on the north and Dorset on the south. The Severn Bore wave, as far as I understand, is a phenomenon of the Severn mouth and does not extend as far as Cardiff, let alone those more western coasts of the Bristol Channel.

Lastly, although no-one has suggested that the tsunami risk is zero, it pays to bear in mind that tsunamis do occur on this coast line. Wherever there are earthquakes, landslides or meteor impacts in water, tsunamis occur. All ocean coasts are hit by tsunamis from time to time. Whether or not the 1607 flood was caused by a tsunami, there is a real, not merely theoretical, tsunami risk for Cardiff and the Bristol Channel coast.

Posted by Stephen
Tuesday, Jan 11, 2005 at 22:30:37

ζ comment

Hi Stephen, Cheers for joining the debate.

I agree that the recorded flood levels are astounding, however, the infamous East Coast flood of 1953 is strong evidence that a storm surge of the magnitudes suggested in the annals is quite possible - King's Lyn recorded a high tide 2.5 metres higher than expected!

Also with regard to the extreme deviations in the daily range - as suggested at Bristol - the diurnal inequality needs to be considered which could potentially shift the expected height by 2 feet depending on the proximity of syzygy to the actual event.

With regards to the Severn Bore, I was not suggesting that this was the direct cause. The bore is simply a product of the tide and, in the case of storm surge coincidence with the syzygy tides, the bore would be exagerated. But this would still only have been experienced in the upper reaches of the Bristol Channel.

Posted by Tom
Thursday, Jan 13, 2005 at 00:11:30

η comment

I must admit to not remembering the 'equation' relative to pressure and tidal lift or decrease but is it not along the lines of 1" per milibar? An extreme low pressure system positioned in the right place can increase the tide by between 4-5ft. The effect of extreme gales again when blowing from the right position directly into the Bristol channel can realistically be expected to increase the high tide mark by 10ft.The written record of a "sodden tuesday morning" and " mighty strong wind" suggest the Flood took place coincident with an extreme low pressure system. It has'nt been considered that the Severn system may have also been saturated by freshwater floods which have a major impact on the tide.In these circumstances the tide cannot reach beyond Stonebench downstream from Gloucester and the high tide flood can produce delayed and devastating effects.To get this in context, it must be pointed out that before weirs were built above gloucester the tide, and its bore, could reach Worcester. Such an effect was felt not many years ago when a 2ft 'bore' swept along the A48 at Minsterworth, the river having overflowed the flood banks. The occassion caught the National Rivers Authority out, who had warned of possible flooding of farmland. A local farmer lost cattle and was referred to in the local paper as to be considering legal action against the NRA.

There are many anecdotal references to bore waves in the Severn of 10ft and higher. These references, whether written or oral tradition are easily dismissed and often so, by sceptics or those who simply are not familiar with the Severn bore phenomenon. Anyone who has witnessed an extreme bore will know that anything may be possible and the inundations associated with the flood tides of history may still occur despite the protection of flood banks not previously in place to protect the countryside.At around the time referred to above a bore wave again near Minsterworth, caused wave wash which reached to the eaves of the bankside houses more than 20ft above the river's surface. Perhaps more regard should be shown for the fact that the Bristol Channel, formerly the 'Severn Sea' has a tide which is the second highest in the World. I believe I am right in saying no other river with a bore has the tidal range of the Severn. It is the combination of exceptional factors which makes any of the historic floods in the Severn, whether recorded in text or earlier oral tradition both exceptional and catestrophic. Returning to my previous comment and reference to Nennius. Of the 13 Wonders of Britain written down by Nennius circa 800AD, from tradition of unknown antiquity the Severn Bore is described several times in different ways, whereas the other wonders get one mention. The Severn bore has in tradition overwhelmed and drowned armies and in history boats, people and cattle amongst damage to property. The Flood of 1606-7 has, on the evidence available, to be recognised as a weather induced occurrence. If there was a tsunami then there must have been two coinciding events. Although this cannot be seen as impossible it is certainly unlikely.

Posted by donny
Thursday, Jan 13, 2005 at 19:07:30

θ comment

If the event was a tsunami should there not be reports of ground tremors from the undersea earhquake, as were reported in Indonesia? A tsunami (see ) operates over a large region so shouldn't there should be reports from other areas such as Cornwall and Ireland at the same time?

Posted by Derek Emery
Wednesday, Jan 19, 2005 at 03:34:03

ι comment

The two dates for the flood are one and the same. The Julian (i.e.Julius Caesar's) calendar had lost 10 days since Roman times. Pope Gregory proposed a new (Gregorian) calendar which jumped 10 days, and changed the start of the year from April to January (and abolished leap years on 3 out of 4 centuries (e.g. 1800, 1900 were not leap years.) Thus 20th January 1606 in the Julian calendar is 30th January 1607 in the Gregorian. Both are the same Tuesday, and a couple of days after full moon - the point with the highest tides.

The fact that it was the highest of the spring tides that winter probably only added a few inches to what was, in any case a spring tide (i.e. the highest of the month).

While one source claims the sun was "fayrly and bryghtly spred", most mention the strong westerly winds and floods coming down the river Severn. A few weeks earlier, possibly the first emigrants had set off to colonise Virginia with three ships. They had to anchor up in the English Channel on the 5th January, "stormbound for more than a month". They eventually made the journey, where they founded Jamestown, but clearly it was a wet and stormy January.

I have been interested in this piece of history for a while. With the 400th anniversary coming up in two years, I think somebody should gather the sources together, and publish them together, so that the whole story becomes clear - from the one man drowned in his bed in Barnstaple, through to the many killed or ruined further up the Channel later that day.

When you hear on TV that the 1953 East coast floods are the country's "worst natural diaster", you realise how quickly such enormous events are forgotten.

Posted by Mike Kohnstamm
Thursday, Jan 27, 2005 at 00:03:45

κ comment

I am just an simple person with no academic knowlege of Tsunami, but my father living in Grenada, West Indies told me a programme informing viewers about the Great Flood in Cardiff 1607 caught my attention, I mentioned to him about 2 weeks ago I got up at about 5.45am as I thought I felt an strong earth tremor: I live in Cardiff and I thought this was very strange, it was such a strong jolt. Now all this information is very interesting for me. Thank you. that is my small contribution. 12 Feb 2005

Posted by June Campbell-Davies
Sunday, Feb 13, 2005 at 09:56:56

λ comment

i am interesting your works

Posted by akin onursal
Tuesday, Feb 15, 2005 at 17:38:32

μ comment

Very interesting and imformative postings, Would anyone happen to know what size and depth would a quake have to be to cause a tsunami along the coast of the uk?

Posted by karen (bad dreams) cardiff
Saturday, Feb 19, 2005 at 22:35:47

ν comment

Great discussion on the 1606/7 flood. I'm hoping one of you very scholarly folks can help me with a question. Presuming that it is late April 19 of 1762. A barque is moored off Goldcliff. It releases a Jolly boat to Bristol Harbor which is rowed to the quay. Later after business is accomplished it is rowed back to the ship at Goldcliff. Now, how do I determine the tides of that day? Would a boat be able to row up the Avon to Bristol and return before dark? Could it ride the receding tide to the ship moored near Goldcliff? (This was before the foating harbors were installed in Bristol in 1800. The tides differed by 30 feet at times according to various sources).

Any ideas?

Posted by Carol S
Thursday, Mar 17, 2005 at 01:58:10

ξ comment

I am a 2nd year ba geography student studying at UWS Swansea. i have recently been advised to study the events of the possible tsunami of 1607 in the Bristol channel. Having read this original article my limited research suggests to me a couple of points. The question of the date can be expained by the change between the gregorian and julian calenders meaning that all accounts relate to the same event. working on the present day calender format this event took place at 9am on tuesday 30th january 1607. With reference to the start of your article where you state that clear blue sky is not reqired for a Tsunami, i believe you must have taken this out of context. it appears to me that the aim of this statement is to say that this great flood happened at a time devoid of normal flood inducing weather. from my reasearch i believe this event was caused by a tsunami and in that light the website; may be of some help to you. you have probably seen this site before, but if no it shows some interesting accounts of this event and portrays the belief that the flooding was tsunami induced. hope this feedback is of some use to you as your site and the above mentioned site have been of use to me.

Posted by Matthew Dumelow
Friday, Mar 18, 2005 at 12:53:42

ο comment

Looks like there is general consensus that the two dates represent one in the same now.

Matthew, with regards to the prevailing weather, I believe there is actually contextual ambiguity in the statement the sky was blue, especially as complement to the clause there is a secondhand report of an earth tremor felt earlier that morning - which is clearly propounded as a tsunami inducing condition.

Whether it is a proposed condition for the presence of a tsunami or the absence of normal flood inducing weather is thus a subjective interpretation of a non-primary source. Tom was merely suggesting that evidence of clear skies is not a valid argument to support a tsunami.

However the alternative interpretation which you raise is worth further consideration. The web page you mention - 1607 Flood in the Bristol Channel - Was it a UK tsunami? - recounts source materials from Bryant and Hasletts' academic paper. In this paper however there is only one historical account of fine weather (the same pamphlet of Disney's article - God's warning to his people of England!), one account which does not describe the weather and two accounts of strong south west winds. Yet from this Bryant and Haslett conclude (as is reiterated on the Burnham pages) that the evidence for a storm surge is contradictory because several historical accounts note a sudden flooding of the coastline under fair weather conditions. A single account of fair weather hardly supports this conclusion!

Besides which surely it is quite possible that local conditions may be fair weather during an intense depression - take the eye of a hurricane. And another account from the period quoted here which states that in 1607 in the Reign of James, the First, a dreadful hurricane happened.

So, to draw the conclusion that the Great Flood was a tsunami event based on the prevailing weather conditions is highly speculative.

It is also worth noting that running the year 1607 through the lunar perigee calculator suggests that the end of January would have experienced a Proxigean tide following the New Moon (after the change of the moone). Of course the algorithm may not be accurate for 400 years ago, but the coincidence of a Proxigean tide with a deep low (or hurricane conditions) could certainly produce the kind of storm surge that could cause the damage and inundation in the annals.

Perhaps it would be valuable to take another angle on this and look at the actual probability of a tsunami of the necessary magnitude actually occurring in the Bristol Channel or Celtic Sea (rather than drawing subjective, and occassionally dogmatic, conclusions from non-primary accounts)? This has been touched on over at UK Weather World.

Posted by Sunya
Friday, Mar 18, 2005 at 15:29:36

π comment

With regards to earthquakes in the Bristol Channel and Celtic Sea, are these not principally caused by transform faults (Variscan Orogenic Belt) - horizontal displacement? Rather than the vertical displacement of subduction zones associated with tsunami formation. Hence cancelling out the likelihood of a tusnami induced by earthquake?

Just a thought?

Posted by The Rock
Friday, Mar 25, 2005 at 13:48:34

ρ comment

The logs have shown a dramatic increase in traffic to this page following the Timewatch programme last Friday. Personally I was highly disappointed by Timewatch's presentation of the facts and their dramatic recreations and conclusions clearly influenced by ratings and climate.

I admit my little wandering into the past at the end of the original post above has no relevance to the discussion in light of the 1606/07 date resolution. Yet it does serve as a good example of the necessity for objectivity in hermeneutic analysis (in short, recreation of the past) - something the makers of Timewatch seem totally oblivious too.

Sunya's fact-filled comment (thankyou) above serves a strong case for the storm surge camp. But I would be interested to hear anyone elses view in light of The Killer Wave. Did the programme convince you that a Tsunami occurred? If so why? Feel free to have your say? (If you even get this far through the discussion!)

Posted by Tom
Monday, Apr 04, 2005 at 03:02:32

ς comment

Since there are still differences of opinion about the cause of the 1607 Bristol Channel flood (storm v tsunami), more work would be useful in two areas - 1) Can Bryant and Haslett's sand sheets be dated? Is there organic matter in the layer that could be carbon-dated for example? That might at least settle whether or not it was laid down in 1607. 2) Are there other areas close to the postulated earth crust movement where similar flooding occurred? What about Dingle Bay or the Kenmare River in S.W. Ireland for example? Or maybe the Baie de Dounarneney in N.W. France near Brest?

Posted by John Hedges
Tuesday, Apr 05, 2005 at 08:24:29

σ comment

In the early 1970s there was an earth tremor over an area that stretched from, as I remember, Cardiff to Hereford. I lived on a farm near Cardiff [part of which would have been flooded in the great flood] and thought the shaking of the house I lived in had been caused by a vehicle driving into it. There was some structural damage to some buildings in the area. The local NFU insurance agent had to send cuttings from the Western Mail to his HQ when he submitted a claim for a fallen chimney pot caused by an earthquake because they did not belive it. The point of all this, in relation to the tsunami theory, is that I remember at the time experts saying one reason for the tremor was the extremely low atmospheric pressure at the time it happened. This can apparently trigger earthquakes or tremors. Perhaps this should be factored in the discussion.

Posted by Rhydd Jones
Thursday, Apr 07, 2005 at 17:30:11

τ comment

In order to consider the evidence that this could be an earthquake induced tsunami it is worth weighing up the following.

The flood happened at the crest of an exceptional spring tide. The chance that a major tsunami should have occurred precisely at this time is very remote. Say (generously) that exceptional springs occur for 4 hrs a month, 48 hrs in a year, ie around 0.5% of the time). That means the odds are 200 to 1 against a tsunami happening to coincide with an exceptional tide. We know that a wind driven storm surge would supplement a spring tide and hence would coincide with it. There are also reports of strong southwesterly winds prior to the flood. For this reason while a tsunami would be the most sensational explanation it would also be the least likely.

The largest earthquake to have occurred in the region around the British Isles (over the past 500 years) had a surface wave magnitude (that gives the best correlation with seismic energy release) of M5.5 and occurred in 1931 in the middle of the North Sea. The attenuation of ground motion is very slow in North-West Europe so that the 1931 earthquake was felt strongly in all the countries that ring the North Sea and caused minor damage along the East coast of England from Yorkshire to Norfolk. The earthquake was still far too small to have generated a tsunami (nor was there one). Typical tsunamigenic earthquakes start at around Magnitude 7 (ie in energy terms around 40 times bigger than the largest earthquake known in this region) and to cause a 3-4m tsunami at a distance of several hundred km as implied by the tsunami explanation, would suggest a magnitude of 7.5 or higher (ie around 200 times bigger in energy terms than the largest known earthquake in NW Europe). An earthquake of M6 or higher anywhere along the Atlantic margin of Ireland in 1607 would have been felt and reported across the whole of NW Europe: throughout Ireland, Britain in France etc. There was no such earthquake at the time of the 1607 flood. There is also no record of any similar tsunami in 1607 along all the other coasts in the region from the Scilies to Cornwall to Brittany to southern Ireland. This is consistent with a storm surge being focused up the Severn Estuary. It is not consistent with a tsunami.

- in 1755 a major Magnitude 8.5 earthquake occurred along the plate boundary to the southwest of Portugal, caused catastrophic damage in towns throughout the southern half of Portugal, was felt across the whole of SW Europe, caused seiching in lakes throughout Britain and Scandinavia and caused a major regional tsunami comparable to that of the Indian Ocean earthquake of 26/12/2004. It was not recorded in the Bristol Channel but was noticed (at low tide) in Cornwall.

Posted by Robert Muir-Wood
Tuesday, Apr 12, 2005 at 13:01:22

υ comment

have there been any tsunamis id the uk,

colin h.

Posted by colin haggart
Sunday, Jun 12, 2005 at 11:02:29

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