The Anglo-Siamese War (or Anglo-Thai War) was a brief state of war that existed between the English East India Company and Kingdom of Siam in 1687–88. Siam officially declared war against the Company in August 1687. No peace treaty was ever signed to end the war, but the Siamese revolution of 1688 rendered the issue moot.
The war resulted in part from the jostling of the great powers—England, the United Provinces and France—for trading influence in Siam. The immediate casus belli was the dispute between Siam and the Company over the actions of the Siamese officials at Mergui (Myeik), which the English considered piracy, and the English response, which included a naval blockade of Mergui. With the exception of the fighting at Mergui on 14 June 1687—which amounted to a massacre of English sailors on shore by the Siamese—the actual war was confined to commerce raiding.
Background
Siamese policy under Phaulkon
By 1681, Siamese foreign policy was in the hands of King Narai's Greek favourite, Constantine Phaulkon. One of Phaulkon's policies was to develop Siamese trade through the port of Mergui on the Bay of Bengal. This was the main Siamese port engaged in trade with the Coromandel Coast of India. This trade was traditionally conducted by Muslims from the Indian Kingdom of Golconda.
To displace the Indian influence, Phaulkon began constructing ships at Mergui. He manned them with English recruits and they sailed under the Siamese flag. The use of English sailors by Siam provoked conflict between the merchants of Golconda, used to dominating the trade of Mergui, and the East India Company, which possessed the Madras Presidency on the Coromandel Coast.
In 1681, the port official at Masulipatam, a port of Golconda, refused to supply cables to Samuel White, an English associate of Phaulkon's, and as a result White's ship foundered. In 1683, Phaulkon appointed another Englishman, Richard Burnaby, as governor of Mergui with White acting as shahbandar (harbourmaster) under him. Together they supervised a large ship-building programme. White, however, seems from the beginning to have used his position to avenge his grievance against Golconda. Burnaby, like Phaulkon, was a former Company employee. Another former Company employee, Thomas Ivatt, was appointed Siamese ambassador to Golconda.
War of reprisals against Golconda
In 1685, Burnaby and White began a series of reprisals against Indian shipping, Golconda in particular. Although Phaulkon ordered him to stop, White came up with various excuses to justify continuing his vendetta against Golconda. These were regarded as mere piracy by the Indians and the East India Company, who blamed Phaulkon and the Siamese government for the acts of their subordinates in Mergui. Golconda also blamed the Company for White's actions since he was an Englishman.
Company documents record White's various actions during his vendetta, including a naval bombardment of Masulipatam, the capture of several merchant vessels and the imprisonment of the crew of the Tiaga Raja, an Indian merchant vessel from Madras from which White seized £2,000 worth of goods during its stay in Mergui. He then seized the ship of the Armenian merchant John Demarcora, a resident of Madras.
Siamese–Company rift
The rift between the Siamese government and the Company was further aggravated by a personal dispute between Phaulkon and the President of Madras, Elihu Yale. Yale had been contracted by Phaulkon to provide some jewellery to King Narai. Phaulkon, however, considering Yale's bill outrageous, refused to receive the jewels when Yale's brother, Thomas, arrived in Ayutthaya. This embarrassment for the Company took place at the same time as the French Chaumont embassy was present (October 1685).
In July 1686, the Company was able to secure from King James II of England an order-in-council forbidding English subjects from serving aboard foreign ships in eastern waters. It did not arrive in Madras until January 1687. In November 1686, Phaulkon wrote to Père François de la Chaise, the confessor of Louis XIV of France, offering to hand over Mergui to the French in order to put an end to White's continued unauthorised piracy.
Open conflict
Blockade of Mergui and massacre of the English
By late 1686, the East India Company was already prosecuting a war specifically against Samuel White's vendetta. An expedition was dispatched from Madras in October 1686 to seize Negrais up the coast from Mergui to use as a base for combatting piracy. It left after the monsoon had changed and was forced to turn back. The campaign against Mergui got off to an inglorious start.