| Conflict: | Third siege of Diu |
| Partof: | Ottoman–Portuguese conflicts (1538–1560) and Gujarati–Portuguese conflicts |
| Date: | 20 April – 10 November 1546 |
| Place: | Diu, Portuguese India |
| Map Type: | India |
| Coordinates: | 20.71°N 70.98°W |
| Result: | Portuguese victory |
| Combatant1: | Portuguese Empire |
| Combatant2: | Gujarat Sultanate Ottoman Empire[1] [2] |
| Commander1: | João de Mascarenhas João de Castro |
| Commander2: | Khoja Zufar |
| Strength1: | 18 May: 440 men[3] 19 July: reinforcements consisting of 20 fustas and 6 caturs with men arrived On 7 November, Governor Castro arrived with 35 fustas, caturs, 3 galeons, naus and gales, with 3,000 Portuguese and 300 Indian men[4] |
| Strength2: | 10,000 men[5] 30 Ottoman ships[6] |
| Casualties1: | More than 200[7] |
| Casualties2: | 3,000 killed 600 prisoners[8] |
The third siege of Diu was a siege of the Portuguese Indian city of Diu by the Ottoman Empire and Gujarat Sultanate in 1546. It ended with a major Portuguese victory.
At the beginning of the 16th century, the Muslim Sultanate of Gujarat was the principal seapower in India. Gujarat fought the Portuguese fleets in collaboration with the Mamluk Sultanate. The Portuguese were defeated by a combined Mamluk-Gujarati fleet in 1508, which was in turn destroyed by a Portuguese fleet in the Battle of Diu (1509). By 1536, the Portuguese had gained complete control of Diu, while the Sultanate of Gujarat was under attack from the Mughals.
In 1538, the Ottoman Empire, which had taken over Egypt (1517) and Aden (1538) from Mamluk Egypt, joined hands with the Gujarat Sultanate to launch an anti-Portuguese offensive. They besieged Diu in 1538, but had to retreat.
After the failed siege of 1538, the Gujarati General Khadjar Safar besieged Diu again in an attempt to recapture the island. The siege lasted seven months from 20 April 1546 to 10 November 1546, during which João de Mascarenhas defended Diu.[9]
A large fleet dispatched by Suleiman would also arrive in Diu and help in the struggle against the Portuguese defenders.[10] [11]
The siege ended when a Portuguese fleet under Governor João de Castro arrived and routed the attackers.[9]
Khadjar Safar and his son Muharram Rumi Khan (who were probably of Albanian origin) were both killed during the siege.[12]