Early conflicts, 1519

The conflicts between Aceh and Portugal started in 1519, when a Portuguese ship under Gaspar de Costa was lost near Aceh and attacked by the Acehnese, killing its crew. Gaspar was captured and later ransomed, and it was not long after this that another ship under Joano de Lima was attacked near Aceh. All its crews were massacred.^[5]

Battle of Aceh, 1521

In 1521, a Portuguese fleet of 6 ships under the command of Jorge de Brito departed from Goa and anchored in the harbour of Aceh, where they found nine Portuguese who had shipwrecked there, led by João de Borba.^[6] Borba told Brito how the sultan of Aceh had attacked and plundered a number of Portuguese vessels who either passed by his shore or were wrecked there.^[7] Brito asked the sultan to return the cargo, but as it was not forthcoming they attempted to sack a temple near the city of Aceh with 200 men. They captured a small settlement half-way between the port and the city of Aceh, but were later driven back aboard by an Acehnese counter-attack, having suffered more than 50 dead.^[8]

Battle of Pedir, 1522

Sultan Ali Mughayat Syah captured the neighbouring Sultanate of Pedir in 1522 by bribing its chief officials.^[9] The sultan of Pedir fled with his family to neighbouring Pasai, where the Portuguese held a fort and requested its captain military aid to recover his throne.^[9] The captain of the fort dispatched Manuel Henriques with 80 Portuguese and 200 auxiliaries to Pedir by sea while the sultan marched by land with a force of 1000 men and 15 elephants.^[9] The Acehnese attacked the Portuguese and killed 35 men including the commander, after which the Portuguese returned to Pasai, suspecting of a trap.^[9]

Siege of Pasai 1523–1524

In 1523 Aceh invaded Pasai, a Portuguese ally and after a few months campaign occupied its capital with much slaughter.^[10] Turning towards the Portuguese fortress that existed there, they sieged it for several months.^[10] The Portuguese, numbering no more than 350 soldiers, many of them sick and wounded, repulsed several assaults, but after gathering a war-council decided to evacuate the fort.^[10][11]

Battle of Aceh, 1528

In 1527, Francisco de Mello sailed in an armed vessel with dispatches to Goa. On his journey, he met a pilgrim Acehnese ship coming from Mecca with a crew of three hundred Acehnese and forty Arabs.^[12] They bombarded and sank it from a distance.^[12] The Portuguese massacred the surviving crews, prompting the Acehnese to seek retaliation. The Acehnese then attacked and captured the Portuguese galley.

Battle of Aceh, 1529

In an attempt to negotiate a treaty of commerce with the Acehnese Sultan, the governor of Malacca dispatched a company with precious gifts and arrived in Aceh, Immediately after they departed, however, some boats followed them and captured them, killing their crews. The governor assumed these ships were lost in accidents.^[13]

The Acehnese sultan, wishing to ratify the treaty, wished for some Portuguese presence. The governor dispatched a large ship under Manuel Pacheco alongside several merchants; when they arrived, they were surrounded by a great number of Acehnese boats, which led to suspicion between the Portuguese. An arrow killed Manuel, and the ship was captured. The crew was arrested and massacred.^[13]

Siege of Malacca, 1537

The first attack launched by Aceh on Malacca in September 1537 was led by Alauddin al-Kahar. This surprise attack, supported by about 3000 fighting men, landed at night near Malacca, and began ravaging the outskirts. However, over the following two nights, the Acehnese force was driven out by the Portuguese with a loss of 500 Acehnese.^[14][15]

Battle of Perlis River, 1547

The Sultanate of Aceh attempted in 1547 to attack Portuguese Malacca by surprise under the command of the King of Pedir Bayaya Soora.^[16] The large Acehnese fleet, which included 3 galleys, 57 lancharas, 5000 men among sailors and warriors, 300 hulubalangs (ourobalões in Portuguese), plus 80 mercenaries from the Ottoman Empire, of which a number were former Janissary defectors was however detected by the Portuguese, ambushed while landing in the middle of the night and forced to withdraw north.^[16][17]

Through the encouragement of renown missionary Francis Xavier the Portuguese assembled a small flottilla and under the command of Dom Francisco de Eça set out after the Acehnese.^[16] Having anchored within Perlis River to try and subjugate the region, the Acehnese were cornered within the river.^[16] After a stiff but brief fight in December 6, almost the entirety of the Acehnese force was destroyed or captured.^[16] The Sultan of Perlis signed an alliance with Portugal and became a tributary vassal in the aftermath.^[16]

Battle of Qishn, 1561

In March or April 1561, a large 50-gun Acehnese ship manned by 500 Acehnese and other nations, including Turks, Arabs, and Abyssinians, was intercepted by a Portuguese fleet of two galleons and some foists near Qishn. A fierce battle ensued till night in which both Portuguese galleons and Acehnese ships caught fire, two of the Portuguese ships burned and drowned, and both sides suffered heavy casualties. The next day, the consort of the ship was spotted, and the Portuguese successfully forced her to engage; however, at night, the ship slipped away. Tired of chasing their prey, the Portuguese disengaged and cruised in the Red Sea for some time.^[18] The remaining crews of the Acehnese ship later arrived in Aden.^[19]

Siege of Malacca, 1568

In 1568 Sultan of Aceh Alauddin attacked Portuguese Malacca. The Ottomans supplied cannonneers to the alliance, but were unable to provide more due to the ongoing invasion of Cyprus and an uprising in Aden.^[20]

The army of the Sultan was composed of a large fleet of long galley-type oared ships, 15,000 troops, and Turkish mercenaries.^{[21][22][23][24]} The city of Malacca was successfully defended by Dom Leonis Pereira, who was supported by the king of Johore.^[21]

Battle of Aceh, 1569

The Battle of Aceh was fought in 1569 off the coast of Sumatra between a lone Portuguese carrack (nau, in Portuguese) and an armada of the Sultanate of Aceh, that was about to stage an attack on Portuguese Malacca with 20 galleys, 20 war junks and 200 smaller craft.^[25][26] It ended in Portuguese victory and the withdrawal of the Aceh fleet after suffering heavy losses.^[25][26]

Battle of Formoso River, 1570

In November 1570, the Portuguese ambushed and destroyed an Aceh fleet of 100 ships by the mouth of River Formoso to the south of Malacca, killing the prince-heir of Aceh, and thus forcing the Sultan to postpone the attack to a later date. Dom Luís de Melo then returned to India with his forces the following January.^[27]

Siege of Malacca, 1573

Portuguese Malacca was scarcely defended in October 1573 as most soldiers were embarked on commercial missions. The sultan of Aceh therefore requested the assistance of the Queen of Jepara in Java to siege it and assembled an armada of 25 galleys, 34 half-galleys, and 30 craft and 7000 men.^[28] Aceh had material support from the Sultanate of Golkonda in India.^[29]

The Acehnese landed on October 13 south of Malacca and dealt severe casualties to the Portuguese who attempted a sortie. Thereafter they began attacking the fortress with incendiary projectiles, causing several fires but a sudden storm put out the fires and scattered the fleet, and the assault was called off. The Aceh commander then decided to establish a naval base by the Muar River and force the city to surrender through a naval blockade instead, but they were challenged by a Portuguese fleet of a carrack, a galleon, and eight half-galleys under the command of Tristão Vaz da Veiga.^[30] Despite having Turkish gunners and cannon, the Acehnese artillery was not overly effective.^[30] Once their flagship captured by the Portuguese, the remainder of the Aceh fleet scattered.^[30] The Portuguese suffered ten dead.^[30]

Siege of Malacca, 1575

After Malacca was sieged in 1573 and 1574, the garrison was left decimated, crops destroyed, and foodstuffs and gunpowder in the city nearly exhausted.

In the final day of January 1575, a new Acehnese armada of 113 vessels, once more laid siege to Malacca.^[31] The Acehnese defeated the Portuguese vessels led by Joao Pereira, Bernadim da Silva, and Fernando Pallares. They killed 75 Portuguese, including the three captains, and captured 40 prisoners. Five Portuguese escaped by swimming.^[32] Within Malacca there were now only 150 Portuguese soldiers to defend it plus the corps of native soldiers; Tristão Vaz realized that to keep them behind the walls could be disadvantageous, as it might hint the enemy of their dwindling numbers.^[33] Because of this, he had his last remaining men perform short sorties to fool the Acehnese of their numbers.^[33]

Ultimately, the third siege of Malacca was brief: only seventeen days after landing, fearing a trap, the Acehnese lifted the siege and sailed back to Sumatra.^[34] In June, Dom Miguel de Castro arrived from Goa with a fleet of a galleass, three galleys, and eight half-galleys to relieve Tristão Vaz as captain of Malacca, along with 500 soldiers in reinforcements.^[35]

Battle of Johor, 1577

On January 1, 1577, the Portuguese fleet led by Mathias de Albuquerque was intercepted near Johor by the Acehnese fleet on their mission to protect a Chinese junk. The Acehnese fleet consisted of 150 ships and 10,000 men and was led by the sultan Ali Ri'ayat Syah I. The Acehnese were defeated and 1,600 were captured, while the Portuguese only suffered 13 deaths.^[36][37]

Battle of Malacca and Johor, 1582

The Acehnese fleet attacked Malacca in 1582. With a fleet of 150 ships, they intercepted two ships lying in a river and began bombarding them. However, seeing the little damage inflicted, they resolved to burn them. However, the Portuguese successfully diverted them from the burning vessels that were sent to burn them. Later, a Portuguese galliot led by Nuno Monteiro with 50 men engaged the Acehnese fleet, which began boarding it. However, the galliot caught fire, and all on board were killed, including Nuno. The Acehnese, satisfied with this success, then retired to attack Johor.^[38]

The Sultan of Johor requested assistance from the Portuguese at Malacca, and 12 ships were dispatched to his aid.^[39] The Acehnese were caught unprepared and some of their largest galleys were torched before any resistance could be organized. The head of one of the Acehnese commanders was presented to the sultan of Johore, who had it set on the beach.^[40] Struck by their losses, the Acehnese lifted the siege shortly afterwards.^[40]

Battle of Aceh, 1606

In 1606, the Portuguese Viceroy of India Dom Martim Afonso de Castro organized a large naval expedition to fight the Dutch VOC in south-east Asia and along the way attack the Sultanate of Aceh.

Having landed and tried to attack the capital of Aceh, the Portuguese encountered heavy resistance, and upon receiving news of a Dutch siege on Malacca, Dom Martim withdrew from the campaign.^[41]

Battle of Formoso River, 1615

In 1615, Iskandar Muda led a successful campaign against Johor with a large fleet of 100 galleys, 150 ghurab, 250 junks, lancharas, calaluzes and about 40,000 men.^[42] On the way back, the sultan intended to attack Portuguese Malacca and anchored his fleet within Formoso River. It was the largest fleet the Acehnese had ever mobilized for an attack against Malacca.^[42]

In what was "one of the bloodiest battles the Portuguese fought in south-east Asia", the Acehnese suffered so much damage they were forced to call off their plans and return to Aceh.^[42][43]

Battle of Perak, 1620

Aceh conquered Perak in 1620. The Acehnese detached 20 ships that sailed to the vicinity of Portuguese Malacca but were detected by the Portuguese and so they sailed away.^[44] The presence of 4 large warships in Malacca demonstrated that the Portuguese were ready to defend their interests in the region against Aceh, Iskander Muda asked the Dutch for assistance against those ships in return for extension of the Contract in Tiku.^[45]

Having gotten information of Aceh activity in Perak, the captain of Malacca dispatched 9 oar vessels under the command of Fernão da Costa to the vicinity of Peark, so as to scout the Acehnese armada and escort a number of Portuguese merchant ships that were expected to arrive.^[44] Fernão da Costa attacked a number of Acehnese ships within the river, and then withdrew.^[44]

Battle of Langat River, 1628

In 1628, the Portuguese at Malacca got reports that an Acehnese fleet had been spotted inside the Langat river. Guessing that the Acehnese expected to go after the city, the captain of Malacca Gaspar Sampaio entrusted Francisco Coutinho to search out for the enemy armada and destroy it.^[46]

Francisco Coutinho moved his 15 half-galleys into the river and a fight started. He ordered to board the Acehnese ships that were closer to the mouth of the river, capturing many. The Acehnese having lost many men, decided to desert every single remaining vessel and 3000 of their men were killed, caught or missing.^[46]

Battle of Duyon River, 1629

The 1629 Acehnese attack on Portuguese Malacca came about in the context of growing presence of vessels of the Dutch VOC and the English EIC in the Indian Ocean. Sultan Iskandar Muda of Aceh sought to capture Malacca before either the EIC or the VOC had done so and replaced the Portuguese as overlords of the most important trade emporium in the strategically paramount Strait of Malacca.^[47]

The relatively modest Portuguese fleet achieved an absolute victory over the Ottoman-allied Aceh in such decisive ways that not a single ship or man of the invading force sent to conquer Malacca got back to its country. The Sultanate of Perak, a vassal of the Sultanate of Aceh, defected to the Portuguese side on the occasion.

Aceh expedition, 1638

When Sultan Iskandar Muda died in 1636, he was succeeded by Iskandar Thani, who sent an ambassador to Malacca to ask for a peace treaty.^[48] In September 1638, the Viceroy of India, Dom Pedro de Silva, became agitated by the advances of the Dutch and sent a new envoy to Aceh. The ships departing from Goa with the envoys met the Dutch ships guarding the entrance to the bay as they approached Weh Island. After a fierce battle, the Portuguese managed to break through the Dutch ships. Although the Acehnese had requested a peace treaty, they captured the Portuguese who landed and massacred them.^[49] Out of 60 Portuguese killed, only the ambassador, Francisco de Sousa de Castro survived the captivity.^[50] He was imprisoned for two years and eight months.^[51] This incident outraged the Portuguese, however no military response was launched due to the war with the Dutch.^[52]