Like the weather, Loch Lomond's history has seldom remained settled for long. The worst scenes of carnage took place in 1236 when the Vikings, under King Hakkon of Norway, carried out a lightning commando raid, laying waste most of the townships on the loch's shores.
These fearful warriors penetrated the British defences by sailing on Arrochar on Loch Long. Magnus, King of Man and son-in-law of Hakkon, is said to have dragged his galleys over the narrow isthmus (one and a half miles wide) from Arrochar on Loch Long to Tarbet in 1263 and then launching into the almost totally undefended loch, a frightful surprise attack.
Their reconnaissance and timing were excellent for, having laid waste the loch shores, they were able to make their escape by sailing down the River Leven to the open sea where galleys waited to pick them up. Disaster finally struck shortly afterwards, when a vicious south westerly drove their overloaded fleet ashore at Largs. Hopelessly outnumbered and with no line of retreat they were cut to pieces by the incensed British troops.
For more information, why not visit Vikingar! in Largs.