Morrison was a villager in Lanark who got married in 1296 to a woman and they had a huge festival to celebrate. Unfortunately, Prima Noctae was enforced, meaning that the noble lords had sexual rights over all wives on the first night of their marriage. This enraged Morrison, who tried to defend his bride and her father, but was nearly killed by English troops. But the wife peacefully went to the noble and mounted his horse, and Morrison became infuriated. When the Scottish under William Wallace rebelled, he joined their forces and when they attacked the castle held by Lord Bottoms, he beat him to death with a ball-and-chain, then spitting on his corpse. He later fought at Stirling and Falkirk, where he was killed. He struck down an English soldier, and when he was about to finish him off, he was hit in the chest by an arrow.