The younger son of the Frankish prince Charles Martel, Pepin's upbringing was distinguished by the ecclesiastical education he had received from the monks of St. Denis. Succeeding his father as the Mayor of the Palace in 741, Pepin reigned over Francia jointly with his elder brother Carloman. Pepin ruled in Neustria, Burgundy, and Provence, while his brother Carloman established himself in Austrasia, Alemannia and Thuringia. The brothers were active in subjugating revolts led by the Bavarians, Aquitanians, Saxons, and the Alemanni in the early years of their reign.
Being well disposed towards the church and Papacy on account of their ecclesiastical upbringing, Pepin and Carloman continued their father's work in supporting Saint Boniface in reforming the Frankish church, and evangelising the Saxons. After Carloman, who was an intensely pious man, retired to religious life in 747, Pepin became the sole ruler of the Franks. He suppressed a revolt led by his half-brother Grifo, and succeeded in becoming the undisputed master of all Francia. Giving up pretense, Pepin then forced Childeric into a monastery and had himself proclaimed king of the Franks with support of Pope Zachary in 751. The decision was not supported by all members of the Carolingian family and Pepin had to put down a revolt led by Carloman's son, Drogo, and again by Grifo.
As King, Pepin embarked on an ambitious program to expand his power. He reformed the legislation of the Franks and continued the ecclesiastical reforms of Boniface. Pepin also intervened in favour of the Papacy of Stephen II against the Lombards in Italy. He was able to secure several cities, which he then gave to the Pope as part of the Donation of Pepin. This formed the legal basis for the Papal States in the Middle Ages. The Byzantines, keen to make good relations with the growing power of the Frankish empire, gave Pepin the title of Patricius. In wars of expansion, Pepin conquered Septimania from the Islamic Ummayads, and subjugated the southern realms by repeatedly defeating Waifer of Aquitaine and his Basque troops, after which the Basque and Aquitanian lords saw no option but to pledge loyalty to the Franks. Pepin was, however, troubled by the relentless revolts of the Saxons and the Bavarians. He campaigned tirelessly in Germany, but the final subjugation of these tribes was left to his successors.
Pepin died in 768 and was succeeded by his sons Charlemagne and Carloman. Although unquestionably one of the most powerful and successful rulers of his time, Pepin's reign is largely overshadowed by that of his more famous son.