After the 1645 Battle of Inverlochy near Fort William, the Clan Lamont took the opportunity to lay waste to the Campbell's territory.

The following year, the powerful Clan Campbell army invaded the Clan Lamont lands, taking their castles of Toward on Cowal and Asgog on the banks of Loch Asgog on South West Cowal.

At Castle Toward the Campbells asked for hospitality, which was given, according to custom, and then slaughtered the Lamonts in their beds, before throwing bodies down the well to poison the water.

The two castles were set alight and razed, and the prisoners were transported by boat to Dunoon, where the Campbells slaughtered over two hundred of Lamont's men, women and children.

Thirty-six men were killed by hanging, while the rest were stabbed to death or buried alive.