He was born Anselmo da Baggio in Milan to a noble family. In 1065, he wrote to Béranger, the Viscount of Narbonne, and to Guifred, the bishop of the city. He praised them for having prevented the massacre of the Jews in their district. He also reminded them that God does not approve of the shedding of blood. The same year, Alexander II warned Landulf VI of Benevento "that the conversion of Jews is not to be obtained by force." He also called for a crusade against the Moors in Spain in the same year.