Battle of Diu, 1509: the sea fight that gave Portugal the Indian Ocean

Diu settled who would rule the sea lanes of the Indian Ocean in the sixteenth century. An Egyptian squadron, sent by the Mamluk sultan to drive the Portuguese out of India, had beaten them at Chaul in 1508 and killed the viceroy's son. Less than a year later the viceroy came for it with all the ships he could gather, and in a single day of fighting in the harbor of Diu the squadron was destroyed.²

Who won the Battle of Diu and why?

Portugal won. Almeida's fleet sailed into the harbor with the wind behind it and boarded or sank the Egyptian ships, which waited at anchor close inshore instead of fighting at sea. Malik Ayaz, the governor of Diu, stayed out of the battle himself and was soon suing for peace, and the victory restored Portuguese command of the Indian Ocean.³

Background: the spice trade and the Mamluk fleet

Vasco da Gama's voyage of 1498 opened the sea route from Portugal to India, and within a few years the Portuguese were trying to take the spice trade from the Muslim merchants who carried it across the Arabian Sea and up the Red Sea to Egypt. The loss was felt in the Egyptian customs houses, and the merchants of the Indian coast asked the Mamluk sultan in Cairo for help against the newcomers.⁴

In 1505 King Manuel sent Francisco de Almeida to India as its first viceroy, with his son Lourenço and 1,500 soldiers in Whiteway's count, 1,600 in Danvers'. Almeida built a fort at Kilwa on the coast of East Africa, sacked towns along that coast and made Cannanore and Cochin, on the Malabar coast of India, the bases of Portuguese power.⁵

The sultan answered with a fleet of twelve ships carrying some 1,500 fighting men, Whiteway and Danvers agree, under a commander the Portuguese called Mir Hocem, the Emir Hussein; Whiteway names him Mir Hashim and Danvers Mir Hozem. The fleet crossed to India and went to Diu, where its commander came to terms with the governor of the port.⁶

Malik Ayaz, governor of Diu

Diu belonged to the Sultanate of Gujarat, and its governor was Malik Ayaz. He had come to Gujarat as a slave, of Georgian or Russian origin according to the TDV Encyclopedia of Islam and Russian according to Whiteway, and had risen in the service of Sultan Mahmud I to govern the coast around Diu. Both describe a capable ruler who for the rest of his life kept the Portuguese out of his port.⁷

Diu was Gujarat's great port, the one harbor of very considerable trade in Whiteway's description, and Danvers writes that in its prosperous days the town alone was said to hold more than 50,000 people. The island, about seven miles long and two wide, lies off the southern tip of the Kathiawar peninsula, separated from the mainland by a narrow channel through a swamp that only small boats could use. On the south side, under a sandstone cliff, a small harbor offered anchorage in two fathoms, about twelve feet, of water.⁸

Chaul and a father's revenge

In early 1508 Lourenço de Almeida took a squadron of eight ships up the coast on convoy duty. At Chaul the Egyptian fleet caught him. The fight went on for days: the Portuguese could not board the Egyptian ships, and the arrival of Malik Ayaz with a large number of light craft turned the battle against them.⁹

When the Portuguese pulled out, Lourenço's ship fouled a line of fishing stakes in the river and began to sink. A cannon ball smashed his leg; he had himself placed against the mainmast to go on directing the fight, and a second shot killed him. Nineteen of his crew survived as prisoners. The Navy Museum in Lisbon counts about 200 Portuguese lost and one ship; Whiteway gives 140 killed and 124 wounded.¹⁰

For the viceroy the Egyptian fleet now had to be destroyed for two reasons. It threatened the whole Portuguese position in India, and it had killed his son. Both Whiteway and Danvers say that revenge came first in his mind.¹¹

The commanders' decisions

Almeida's term was over. Afonso de Albuquerque, named by the king to succeed him, reached Cannanore in December 1508 and asked to take over the government. The viceroy put him off until his return from Diu, and Albuquerque went to Cochin to wait.¹²

Three of Albuquerque's captains had deserted him at Ormuz and brought their ships to India, and the viceroy received them without reproach. Whiteway, who judges Almeida harshly, thinks revenge shaped all his choices that winter: to him those ships were above all more strength for the fleet that would avenge his son.¹³

The viceroy gathered all the strength he had. Danvers counts nineteen ships and 1,600 men, 400 of them Malabaris from Cochin; Whiteway eighteen ships and 1,200 men; the Navy Museum 1,000 to 1,500 men, supported by about 400 Malabaris.¹⁴

The allies chose to wait for him. Their ships stayed at anchor close inshore, under the guns of the town, rather than meet the Portuguese at sea.¹⁵

Malik Ayaz played both sides. Whiteway thinks he had been negotiating with the viceroy and had agreed to help him in secret; Danvers writes that he lent Mir Hocem his vessels but stayed out of the battle himself; and Correia says that he meant to seize the Egyptians as a gift for the viceroy if they were beaten.¹⁶

The voyage north

The fleet sailed from Cannanore, on 25 November 1508 according to the Navy Museum and on 12 December according to Whiteway. On the way north it sacked coastal towns, and on 2 February 1509 it reached the bar of Diu.¹⁷

The fleets

The Navy Museum lists five large naus and four smaller ones, round and lateen-rigged caravels, galleys and a brigantine. The viceroy sailed in the great nau Flor de la Mar, the flagship from which the signal to attack was given.¹⁸

Counts of the allied fleet differ widely. Whiteway gives the twelve Egyptian ships and about a hundred other sail, few of them worth much in battle except four large ships of Gujarat; the Navy Museum six large naus, six Turkish galleys and about 110 smaller craft; Danvers 200 vessels in all. Most of them were fustas and paraus, the light oared boats of the coast, from Diu and from Calicut. Correia's chronicle lists ten galleys and ten large ships, a great ship of Malik Ayaz with 700 fighting men and four more ships of Gujarat, besides 120 fustas of Malik Ayaz, 150 from Calicut and 20 from Dabul.¹⁹

The battle in the harbor

The plan was to close with the enemy and board. The sources disagree on the hour. Danvers has the signal given between nine and ten in the morning; Correia and Whiteway have the fleet go in around midday, when the sea breeze rose behind it, and fight on until nightfall. The Portuguese had the wind with them and came under fire from the town's guns as they entered.²⁰

The first blow fell on the Egyptian flagship, although the accounts tell it differently. In Correia's version the Santo Espírito of Nuno Vaz de Castelo Branco led the attack and sank her with a shot at the waterline; the Navy Museum credits the ship of Pêro Barreto with putting the flagship and Mir Hocem out of the fight, and says that the Santo Espírito was hit but fought on. Mir Hocem himself was wounded and escaped ashore.²¹

The Portuguese then grappled the anchored ships one by one and fought their way aboard; Whiteway calls the fight a confused melee that lasted until night.²²

Correia thought that the allies' choice to fight at anchor, with the shore behind them, saved the Portuguese. On the open sea, he wrote, the enemy were so many that the Portuguese would have been worn out by their numbers, had their guns not sent ship after ship to the bottom.²³

By nightfall the allied fleet was destroyed. The Navy Museum counts four large ships sunk and six ships and two galleys captured, besides many fustas and paraus sent to the bottom; Danvers writes that the captured ships were plundered and burned, except four ships and two galleys that the viceroy kept. The town itself was not attacked.²⁴

Counting the losses

For a battle of this size the Portuguese losses were light, but the figures differ. The Navy Museum gives about 30 killed and some 300 wounded, with no ship lost; Correia counts more than a hundred dead, nearly all of them from gunfire, and over 300 wounded; Whiteway speaks only of comparatively little loss. On the allied side the Navy Museum counts more than 3,000 dead. Correia gives no figure, but writes that most of the allied dead were drowned.²⁵

After the battle

Malik Ayaz hurried to make his peace with the viceroy and handed over the surviving Portuguese prisoners taken at Chaul; Whiteway counts seventeen of them still alive.²⁶

The viceroy, who had let his beard grow since his son's death, now had it trimmed, as both Whiteway and Correia record. His revenge also fell on the captives. Whiteway writes that on the way back down the coast prisoners were executed and their limbs fired from the guns over Muslim towns, and Correia tells of prisoners hanged by the feet from the yards of a captured galley.²⁷

Almeida reached Cochin on 8 March 1509 and still refused to hand over the government. Albuquerque was confined to his house for months, and only after a fleet under the Marshal of Portugal arrived from Lisbon did the viceroy give way, in November 1509. On the voyage home he went ashore with some 150 men to punish the local people at a watering place near the Cape of Good Hope, and was killed there with some sixty of them (Whiteway counts twelve leading noblemen and fifty others; Danvers says some fifty), on 1 March 1510 in Whiteway's account.²⁸

What Diu decided

The Navy Museum calls Diu a decisive battle in the strict sense, one in which a side loses all its naval power. It left the Portuguese in command of the Indian Ocean for about thirty years, until the Ottomans challenged them with the first siege of Diu in 1538.²⁹

Malik Ayaz drew his own lesson. He fortified Diu with a stone tower and a heavy chain across the approach, built a fort and a stone bridge to the mainland, and as long as he lived the Portuguese never got the foothold in Diu that they wanted.³⁰