Landulf of Saint Paul (floruit 1077–1137), called Landulf Junior to distinguish him from Landulf Senior, was a Milanese historian whose life is known entirely from his main work, the Historia Mediolanensis. He presents a unique and important point of view from the conflict-ridden years of 1097–1137 in Milan. He thrice sojourned in France while his ecclesiastical faction—the Pataria—was out of favour in Milan, and there learned under some of the leading philosophers of western Europe. After 1113, Landulf's primary ambition was to regain the priesthood in the church of San Paolo which he had lost, and to this end he communicated with popes and emperors. He played a role—large in his own account—in the election of Conrad of Hohenstaufen as King of Italy in 1128.
Landulf's birth year can be approximated from his statement that he was "sixty years old" (sexagenariae aetatis) in 1136. He was a nephew and student of Liprando, a Milanese priest and one of the leaders of the Pataria in the last quarter of the eleventh century. Towards the end of the century, Landulf became an acolyte (acolitus), which was recognised as the highest-ranking of the minor orders in Milan at the time. He held this rank for the rest of his life. In 1095–96, Landulf studied under master Andrea Dalvolto, a priest of the church of San Tecla. Among his fellow students was Nazario Muricola, later his enemy. Later, probably in 1102, he went to Orléans to study under the masters Alfred and James. He may have been avoiding the conflict between the Patarenes, led by Liprando, and the new Papally-approved archbishop, Grosolanus. He was absent from Milan in 1103, when his uncle passed a trial by ordeal.
Landulf returned to Milan, but left for France again in 1106. There he stayed for a year and a half with the prominent reforming Milanese churchmen Anselmo della Pusterla and Olrico da Corte, perhaps acting as their secretary. In Tours he sat under the teaching of a master Alfred, perhaps the same one that had taught him half a decade earlier in Orléans, and in Paris he received lessons from the philosopher William of Champeaux. In 1107, Landulf returned again to Milan and escorted his uncle back from exile at Civate.