Prince William Augustus (1721-1765) was a younger son of George II of Great Britain. He became (a very young) Duke of Cumberland in 1726.
In December 1742, he became a major general in the British army, and saw active service in Germany. Following the Battle of Dettingen (1743) he was made a lieutenant general. In 1745, aged 23, he was given the honorary title of Captain-General of the British land forces and in Flanders became Commander in Chief of the allied British, Hanoverian, Austrian and Dutch troops – although he didn’t do very well against the French in this role.
Nonetheless, during the Jacobite Rising of 1745, he was chosen to put a stop to Charles Stuart’s ambitions for the British crown. He crushed the Jacobite army at the infamous Battle of Culloden in 1746. His ruthless treatment of the defeated Jacobites on the field of battle, and his brutal pursuit and persecution of off those believed to be sympathetic to the Jacobite cause in the aftermath, earned him the name Butcher Cumberland. On his orders, all troops believed to be rebels were killed, 'rebellious' settlements were burned, livestock was confiscated on a large scale, over a hundred rebels were hanged, women were imprisoned and droves of people were sent by ship to London for trial, many dying on route.
After Culloden, his military career was largely unsuccessful, and from 1757 he switched his attentions to politics and horse racing.