Complex sentence: In 931 he entered service as page to Hugh of Arles, who kept court at Pavia as King of Italy and who married the notorious and powerful Marozia of Rome; he was educated at the court and became a cleric at the Cathedral of Pavia.
Split into simpler sentences: In 931 he entered service as paige to Hugh of Arles, who kept court at Pavia as King of Italy and who married the notorious and powerful Marozia of Rome. He was educated at the court and became a cleric at the Cathedral of Pavia.