Arsinoe (Greek: Ἀρσινόη) or Arsinoites or Cleopatris or Cleopatra, was an ancient city at the northern extremity of the Heroopolite Gulf (Gulf of Suez), in the Red Sea.
Arsinoe was the capital of the Heroopolite nome, and one of the principal harbors belonging to Egypt. It appears to have been also denominated Cleopatris (Strabo p. 780) and Arsinoites (Plin. v. 9. § 9; Orelli, Inscr. 516). It is also conjectured to have stood on the site of the biblical Pi-hahiroth (Pihachiroth). Exod. xiv. 2, 9; Numb. xxxiii. 7; Winer, Biblioth. Realwörterb. ii. p. 309. The modern Ardscherúd, a village near Suez, corresponds to this Arsinoe. It was seated near the eastern termination of the Royal canal, which communicated with the Pelusiac branch of the Nile, and which Ptolemy Philadelphus carried on from the Bitter Lakes to the head of the Heroopolite gulf. Arsinoe (Plin. v. 12) was ca. 200 km from Pelusium.
The revenues of the Arsinoite nome were presented by that monarch to his wife (who was also his sister), Arsinoe II of Egypt, after whom the city was named, and remained the property of successive queens or princesses of the Lagid family. The shortness of the road across the eastern desert and its position near the canal were the principal advantages of Arsinoe as a staple of trade. But although it possessed a capacious bay, it was exposed to the south wind, and the difficulties which ships encountered from reefs in working up the gulf were considerable. Arsinoe, accordingly, was less eligibly situated for the Indian traffic than either Myos Hormos or Berenice. In common, however, with other ports on the Red Sea Arsinoe improved in its commerce after the conquest of Egypt by the Romans. One hundred and twenty vessels annually sailed from Egyptian havens to bring from western India silk, precious stones, and aromatics (Gibbon, D. and F. ch. vi).