The –Portugueseconflicts–Ottoman-Portuguese conflicts (1538 to 1559) were a period of conflict during the Ottoman–Portuguese confrontations and series of armed military encounters between the Portuguese Empire and the Ottoman Empire along with regional allies in and along the Indian Ocean, Persian Gulf, and Red Sea.
Background
After the voyages of Vasco da Gama, a powerful Portuguese Navy took control of the Indian Ocean in the early 16th century. It threatened the coastal cities of the Arabian Peninsula and India. The headquarters of the Portuguese was Goa, a city on the west coast of India, captured in 1510.
Ottoman control of the Red Sea meanwhile began in 1517 when Selim I annexed Egypt to the Ottoman Empire after the Battle of Ridaniya. Most of the habitable zone of the Arabian Peninsula (Hejaz and Tihamah) soon fell voluntarily to the Ottomans. Piri Reis, who was famous for his World Map, presented it to Selim just a few weeks after the sultan arrived in Egypt. Part of the 1513 map, which covers the Atlantic Ocean and the Americas, is now in the Topkapı Museum. The portion concerning the Indian Ocean is missing; it is argued that Selim may have taken it, so that he could make more use of it in planning future military expeditions in that direction. In fact, after the Ottoman domination in the Red Sea, the Turco-Portuguese rivalry began. Selim entered into negotiations with Muzaffar Shah II of Gujarat, (a sultanate in northwest India), about a possible joint strike against the Portuguese in Goa. However Selim died in 1520.
In 1525, during the reign of Suleiman I (Selim's son), Selman Reis, a former corsair, was appointed as the admiral of a small Ottoman fleet in the Red Sea which was tasked with defending Ottoman coastal towns against Portuguese attacks. In 1534, Suleiman annexed most of Iraq and by 1538 the Ottomans had reached Basra on the Persian Gulf. The Ottoman Empire still faced the problem of Portuguese controlled coasts. Most coastal towns on the Arabian Peninsula were either Portuguese ports or Portuguese vassals. Another reason for Turco-Portugal rivalry was economic. In the 15th century, the main trade routes from the Far East to Europe, the so-called spice route, was via the Red Sea and Egypt. But after Africa was circumnavigated the trade income was decreasing. While the Ottoman Empire was a major sea power in the Mediterranean, it was not possible to transfer the Ottoman Navy to the Red Sea. So a new fleet was built in Suez and named the "Indian fleet". The apparent reason of the expeditions in the Indian Ocean, nonetheless, was an invitation from India.
This war took place upon the backdrop of the Ethiopian–Adal War. Ethiopia had been invaded in 1529 by the Ottoman Empire and local allies. Portuguese help, which was first requested by Emperor Dawit II in 1520, finally arrived in Massawa during the reign of Emperor Galawdewos. The force was led by Cristóvão da Gama (second son of Vasco da Gama) and included 400 musketeers, several breech-loading field guns, and a few Portuguese cavalrymen as well as a number of artisans and other non-combatants.
Course of hostilities
Siege of Diu, 1538
Major hostilities between Portugal and the Ottoman Empire began in 1538, when the Ottomans assisted the Sultanate of Gujarat with about 80 vessels to lay siege to Diu, which had been built by the Portuguese in 1535. The Ottoman fleet was led by Suleiman I's governor of Egypt Suleiman Pasha, but the attack was not successful and the siege was lifted.
Bahadur Shah, the son of Muzaffer II, the ruler of Gujarat who had negotiated with Selim, appealed to Constantinople for joint action against the Portuguese navy. Suleiman I used this opportunity to check Portuguese domination in the Indian Ocean and appointed Hadim Suleiman Pasha as the admiral of his Indian Ocean fleet. Hadim Suleiman Pasha's naval force consisted of some 90 galleys. In 1538, he sailed to India via the Red and Arabian Seas, only to learn that Bahadur Shah had been killed during a clash with the Portuguese navy and his successor had allied himself with Portugal. After an unsuccessful siege at Diu, he decided to return. On his way back to Suez, however, he conquered most of Yemen, including Aden. After the expedition, Hadim Suleiman was promoted to grand vizier.