Born on 11 November 1082 in
Viscounty of Rodez,
County of Toulouse,
Francia, he was the son of
Ramon Berenguer II. He succeeded his father to co-rule with his uncle
Berenguer Ramon II. He became the sole ruler in 1097, when Berenguer Ramon II was forced into exile.
During his rule Catalan interests were extended on both sides of the
Pyrenees. By marriage or
vassalage he incorporated into his realm almost all of the Catalan counties (except
Peralada). He inherited the counties of
Besalú (1111) and
Cerdanya (1117) and in between married
Douce, heiress of Provence (1112). His dominions then stretched as far east as
In alliance with the Count of
Urgell, Ramon Berenguer conquered
Balaguer. He also established relations with the Italian maritime republics of
Genoa, and in
1114 and 1115 attacked with Pisa the then-Muslim islands of
 They became his tributaries and many Christian slaves there were recovered and set free. Ramon Berenguer also raided mainland Muslim dependencies with Pisa's help, such as
Tortosa. In 1116, Ramon traveled to Rome to petition
Pope Paschal II for a crusade to liberate Tarragona.
 By 1118 he had captured and rebuilt
Tarragona, which became the
metropolitan seat of the church in Catalonia (before that, Catalans had depended ecclesiastically on the
archbishopric of Narbonne).
In 1127, Ramon Berenguer signed a
commercial treaty with the
 Toward the end of his life he became a
 He gave his five Catalan counties to his eldest son
Ramon Berenguer IV and Provence to the younger son
He died on 23 January/19 July 1131 and was buried in the
Santa Maria de Ripoll monastery.