Jordan I, count of Aversa and prince of Capua from 1078 to his death, was the eldest son and successor of Prince Richard I of Capua and Fressenda, a daughter of Tancred of Hauteville and his second wife, also named Fressenda, and the nephew of Robert Guiscard, duke of Apulia, Calabria, and Sicily. He, according to William of Apulia, "equalled in his virtues both the duke and his father."