 In the same year, Sergius IV's sister died and her husband, Rainulf Drengot, returned to Pandulf's allegiance.Broken in spirit, Sergius retired to the monastery of the Holy Saviour "in insula maris", where the Castello del'Ovo now stands.He was succeeded by his son John V, who allied with Guaimar IV of Salerno, another enemy of Pandulf's.