February 3, 1509

Battle of Diu (1509)

Portuguese forces destroy the Mamluk squadron off Diu but fail to capture the port

The Portuguese destroyed the Egyptian squadron — then found Diu's harbour chain raised and the supposed victors locked outside.

About nine in the morning, 3 February 1509

At about 09:00 on 3 February 1509, Francisco de Almeida signalled his ships to advance on the fleet lying off Diu, on Gujarat's coast. He had assembled the force after Hussein al-Kurdi and Malik Ayyaz beat a Portuguese squadron at Chaul the year before and killed his son Lourenço.

The Portuguese closed with Hussein's Mamluk vessels, pinned individual ships between several of their own, and boarded them. Hussein's flagship and most of his squadron were lost.

Gunboats, rescue craft, and a chain across the harbour

Malik Ayyaz brought Gujarati gunboats out to assist Hussein, while smaller Malabar vessels pulled men from the water and carried supplies. Hussein himself escaped.

After the last Egyptian vessel was beached, boarded and burned, Ayyaz withdrew his surviving forces behind Diu's harbour chain. The Portuguese ships stayed outside it, facing the chain, shore guns, soldiers and the Gujarati craft still afloat.

Almeida sails away without the port

Almeida wanted the surviving Egyptians handed over for execution. Ayyaz refused.

Almeida negotiated instead for the Portuguese prisoners taken at Chaul, obtained their release, and left without capturing Diu. Ayyaz still held the city and still had a functioning Gujarati fleet.

How many Portuguese died is unclear. The familiar figure of 40 is probably a dropped zero — the underlying chronicle opens with 1,600 personnel and later accounts for only 1,200 — and Cameron Winter argues that 400 fits the text better.

Sources

Researched 23 Aug 2026 3 sources not yet audited

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What the sources leave uncertain

The principal engagement is securely dated 3 February, although Portuguese ships sighted Diu and preliminary maneuvering occurred on 2 February.
Casualty figures are highly unreliable. A Portuguese text's familiar figure of 40 deaths is probably a dropped-zero error: it begins with 1,600 personnel but later accounts for only 1,200. Cameron Winter argues that 400 deaths better fit the text, while other sources give materially different totals.
Sources disagree sharply over whether the outcome should be called a decisive Portuguese victory, a Pyrrhic victory, or a strategic draw. Destruction of the Egyptian squadron is clear; Portuguese failure to take Diu is equally clear.