Ramon Berenguer IV, Count of Barcelona

Ramon Berenguer IV (c. 1114–1162), sometimes called the Saint, inherited the county of Barcelona from his father Ramon Berenguer III in 1131. In August 1137 he was betrothed to Petronilla, the infant heiress of Aragon.

When her father Ramiro II withdrew to a monastery that November, Ramon Berenguer took charge of Aragon as prince, forging the dynastic union of Barcelona and Aragon that became the Crown of Aragon. He styled himself count of Barcelona and prince of the Aragonese.

The two lands retained their own laws and institutions. He died in Piedmont in August 1162, leaving his son Alfonso II to inherit both Aragon and Barcelona.