Jamieson, Fausset and Brown on Daniel 11:22

22. shall they be overflown ... before him--Antiochus Epiphanes shall invade Egypt with overwhelming forces.

prince of the covenant--Ptolemy Philometer, the son of Cleopatra, Antiochus' sister, who was joined in covenant with him. Ptolemy's guardians, while he was a boy, sought to recover from Epiphanes Coelo-Syria and Palestine, which had been promised by Antiochus the Great as Cleopatra's dowry in marrying Ptolemy Epiphanes. Hence arose the war. Philometer's generals were vanquished, and Pelusium, the key of Egypt, taken by Antiochus, 171 B.C.