William, whose nickname suggests some amount of badassary but was actually just a reference to the lion on his royal standard, joined the revolt in the hope of wresting control of Northumbria away from the English king. At Alnwick, William charged the English forces himself, shouting hubristically: ‘Now we shall see which of us are good knights.’
Clearly, it wasn’t him. He was unhorsed, captured, and taken in chains to Newcastle, then Northampton, and then to Falaise in Normandy while Henry sent an army to Scotland to occupy the country. William was forced to acknowledge Herny as his feudal superior and pay for the cost of his own country’s occupation by taxing his people. That went over super well, triggering a revolt in Galloway that lasted until 1186. The treaty remained in place for 15 years and was terminated when Richard the Lionheart, needing money to take part in the third crusade, agreed to end it in return for 10,000 silver marks in 1189.