He was the son of John I of Egmond and his wife, Guida of IJsselstein. From 1372, he was a member of the ministerial council of Albert of Bavaria. In 1394 he founded a Cistercian monastery outside the walls of IJsselstein. In Egmond aan den Hoef he renovated the chapel at the ancestral castle, surrounded the castle with a moat, and had a canal dug to connect it with Alkmaar. In 1396, he participated in the military campaign in West Friesland. In 1398, he was enfeoffed with the Lordships of Ameland and De Bilt. He was commander of the Dutch troops who were tasked with stabilizing Frisia. There was a dispute with Count William VI of Holland, because Arnold supported the Cod side in the Hook and Cod wars.