Peter IV of Aragon

Peter IV the Ceremonious (5 September 1319 – 6 January 1387), son of Alfonso IV and Teresa d'Entença, ruled the Crown of Aragon from 1336 and spent his reign fighting the noble unions that limited the crown. In 1344 he deposed James III of Majorca and took over his kingdom.

With no son, Peter tried to name his daughter Constance heir over his brother James of Urgell; when James died suddenly in 1347, many suspected poison. The Valencian Union held Peter under guard until he escaped in 1348. On 21 July 1348 he crushed the unionists at Epila, and had the Union's meeting bell melted down and poured down its leaders' throats.

From 1356 to 1375 he fought Castile in the War of the Two Peters, which ended without a winner, and in 1381 became Duke of Athens and Neopatria. He died in Barcelona, aged 67.