1014AD is marked by a large ammonium spike (Mike Baillie, New Light on the Black Death) and in the Anglo-Saxon Chronicle, a huge sea flood was responsible for killing many people in England. The latter occurred on September 28th of 1014 – and the Viking colony of Dublin appears to have largely been abandoned in the same year. Now, it would be nice to link the sea flood with the Viking abandonment of Leinster – but according to tradition, Brian Boru, High King of Christian Ireland, defeated the Vikings in April of 1014 – and the survivors fled. They appear to have ended up on the other side of the Irish Sea, in NW England.
Chris Catling, in Current World Archaeology 66 (August, 2014) page 64 (available in WH Smith's)(see also www.world-archaeology.com) says there was a fashion for overblown adventure stories in the 15th and 16th centuries, such as Zarco's tale of the Portuguese colonisation of Madiera. It seems that the Vikings had arrived long before them (quoting an article in Proceedings of the Royal Society B, summer of 2014). Not only that there is good evidence that corsairs and other North African sailors had been to Madiera before the Portuguese – and even earlier, the Greeks and the Romans. Such adventure stories often owed a great deal to Homer's Odyssey and the Iliad – and cites Hakluyt's Voyages as a prime example. However, according to a Cambridge academic, Dr Mairie Ni Mhaunaigh, the use of Homer goes back even earlier. She has shown, it is claimed, the standard account of the battle of Clontarf, 'Cogadh Gaelhal re Gallaibh' (The War of the Irish against the Foreigners) is largely a rewrite of Homer's account of the Trojan War. The Irish, under Brian Boru, fought against the Dublin based Vikings and their allies, the king and people of Leinster, and basically, sent them packing. It is alleged the parallels in imagery, terminology and the action, was not due to plagiarism, as such, but the idea was to include Ireland in a great literary tradition with roots in the Classical world. Catling adds – perhaps this is why archaeologists have never found any physical evidence for the Battle of Clontarf. It was basically a story – and that is a warning to those who seek to interpret archaeology through the lens of historical narrative. The latter can be distorted.
However, the fact is that the Vikings did largely abandon the Dublin foothold they had created. If the battle is exaggerated and then the sea flood may after all have been responsible. Something to think about.