Ramon Berenguer III (born 1082—died 1131, Barcelona [Spain]) was the count of Barcelona during whose reign (1097–1131) independent Catalonia reached the summit of its historical greatness, spreading its ships over the western Mediterranean and acquiring new lands from the southern Pyrenees to Provence. He was also known as Ramon Berenguer I of Provence.
The son of Ramon Berenguer II, he took the throne on the departure of his uncle, Berenguer Ramon II, and spent his early years fighting off Almoravid Muslims, whose armies approached the very walls of Barcelona. Thereafter, his expansionist campaigns began. In 1111 he conquered the county of Besalú and, by his marriage to Douce (or Dolça) of Provence in 1112, acquired the county of Provence. In the years 1114–15 he undertook, with the Pisans, a joint expedition against the Balearic Islands, liberating thousands of Christian slaves and destroying the Moors’ piratical bases. Commerce thereafter flourished between Barcelona, Marseille, Genoa, and Pisa. The following year (1116) he sailed to Rome in an attempt to gain aid from the Italian states and to acquire a license from the Pope for his crusade in Spain, but the visit was largely unsuccessful. In 1117 he inherited the old county of Cerdaña in the Pyrenees.
On his death, Provence went to his younger son, Berenguer Ramon (as Berenguer Ramon I of Provence, reigning 1131–44); and the rest of the lands, the most important ones, went to the elder son, Ramon Berenguer IV.