Pope Alexander II, born Anselm of Baggio, was the head of the Roman Catholic Church and ruler of the Papal States from 1061 to his death in 1073. Born in Milan, Anselm was deeply involved in the Pataria reform movement. Elected according to the terms of his predecessor's bull, In nomine Domini, Anselm's was the first election by the cardinals without the participation of the people and minor clergy of Rome. He also authorized the Norman Conquest of England in 1066.

The pataria was an eleventh-century Catholic movement focused on the city of Milan in northern Italy, which aimed to reform the clergy and ecclesiastic government within the city and its ecclesiastical province, in support of papal sanctions against simony and clerical marriage. Those involved in the movement were called patarini, patarines or patarenes, a word perhaps chosen by their opponents, the etymology of which is uncertain. The movement, associated with urban unrest in the city of Milan, is generally considered to have begun in 1057 and ended in 1075.