On January 20, 1607 a sudden inundation of the sea coast along both sides of the Severn estuary covered hundreds of square miles in sea water and killed many inhabitants, both people and animals. At least twelve villages appear to have permanently erased.
The cause is generally accepted to have been a storm surge combined with a spring tide and perhaps some rain-swollen rivers, although in 2004 an argument was advanced that the devastation was caused by a tsunami,1 based partly on geological evidence and partly on a few of the contemporary accounts like this description from a Welsh author in the pamphlet Gods warning to his people of England:
For upon the Tuesday being the 20 of January last ... about nine of the clocke in the morning, the Sunne being most fayrely and brightly spred, many of the Inhabitantes of those Countreys before mentioned, prepared themselves to their affayres ... Then they might see & perceive a far of, as it were in the Element, huge and mighty Hilles of water, tumbling one over another, in such sort as if the greatest mountaines, in the world, had over-whelmed the lowe Valeyes or Marshy grounds. Sometimes it so dazled the eyes of many of the Spectators, that they immagined it had bin some fogge or miste, comming with great swiftnes towardes them: and with such a smoke, as if Mountaynes were all on fire: and to the view of some, it seemed as it: of thousandes of Arrowes had bin shot foorth all at one time, which came in such swiftnes, as it was verify thought, that the Fowles of the ayre could scarse fly so fast, such was the threatning furyes thereof.There are three published accounts of the tragedy in 1607 (one pamphlet came out in two editions in same year), it is memorialized in a variety of church plaques recording the height of the water, and it is mentioned in Camden and in several parish records.
1 Simon K. Haslett and Edward A. Bryant, "The AD 1607 Coastal Flood in the Bristol Channel and Severn Estuary: Historical Records from Devon and Cornwall (UK)," Archaeology in the Severn Estuary 15, no. 81–89 (2004). The argument for storm surge was argued most recently in Kevin Horsburgh and Matt Horritt, "The Bristol Channel Floods of 1607 –reconstruction and Analysis," Weather 61, no. 10 (October 1, 2006): 272–77.
Anon. A True Report of Certaine Wonderfull Ouerflowings of Waters, Now Lately in Summerset-Shire, Norfolke, and Other Places of England Destroying Many Thousands of Men, Women, and Children, Ouerthrowing and Bearing Downe Whole Townes and Villages, and Drowning Infinite Numbers of Sheepe and Other Cattle. London, 1607.
---. Lamentable Newes out of Monmouthshire in VVales Contayning, the Wonderfull and Most Fearefull Accidents of the Great Ouerflowing of Waters in the Saide Countye, Drowning Infinite Numbers of Cattell of All Kinds, as Sheepe, Oxen, Kine and Horses, with Others: Together with the Losse of Many Men, Women and Children, and the Subuersion of Xxvi Parishes in Ianuary Last 1607. London, 1607.
---. More Strange Newes: Of Wonderfull Accidents Hapning by the Late Ouerflowings of Waters, in Summerset-Shire, Gloucestershire, Norfolke, and Other Places of England. London, 1607.
Jones, William of Usk. Gods Warning to His People of England By the Great Ouer-Flowing of the Vvaters or Floudes Lately Hapned in South-Wales and Many Other Places. Wherein Is Described the Great Losses, and Wonderfull Damages, That Hapned Thereby: By the Drowning of Many Townes and Villages, to the Vtter Vndooing of Many Thousandes of People. London, 1607.