Arechis II (also Aretchis, Arichis, Arechi or Aregis) (died 26 August 787) was Duke (and later Prince) of Benevento, in southern Italy, from 758 until his death. While he sought to expand Benevento's influence into areas of Italy still controlled by the Byzantine Empire, he also had to resist attacks by Charlemagne, who was building a Frankish empire and had conquered northern Italy.Arechis descended from the Lombards who had invaded the Italian peninsula in the late sixth century and established a Lombard kingdom in northern Italy with its capital at Pavia, and two independent duchies in southern Italy, at Spoleto and Benevento.