The Battle of Diu sometimes referred as the Second Battle of Chaul was a naval battle fought on 3 February 1509 in the Arabian Sea, near the port of Diu, India, between the Portuguese Empire and a joint fleet of the Sultan of Gujarat, the Mamlûk Burji Sultanate of Egypt, the Zamorin of Calicut with support of Ottomans, the Republic of Venice and the Republic of Ragusa (Dubrovnik).