Seeing the Ming Empire distracted by the rebellion in its Mornaean colony, Britain seized the opportunity to expand its influence in Southeast Asia, formally declaring war in 1784. The Royal Navy blockaded Ming territories in the South China Sea while the English Indies Company (EIC) launched an invasion of Siam using a force composed largely of Bengali and Burmese troops. Initially, the British achieved tactical success, defeating Siamese forces at the Battle of Pai in 1785. However, the Ming court decided to prioritize the threat on their own borders over the distant colonial uprising, deploying Imperial regulars to bolster their Southeast Asian tributaries and halting the British advance.

The British offensive unraveled completely in 1786 during the disastrous Battle of Sik in Malaya. Suffering from disease, poor logistics, and false intelligence regarding reinforcements, EIC commander Henry Ratcliffe launched a desperate attack against a numerically superior Ming-Siamese army. The well-equipped Ming forces utilized their artillery advantage to decimate the EIC troops, inflicting massive casualties and forcing the British into a chaotic retreat that effectively destroyed their military presence in the region.

Simultaneously, the Royal Navy suffered a humiliating defeat at sea during the Battle of Hainan. A British fleet, scattered by a typhoon that damped their gunpowder stores, was intercepted by a Ming naval force. Unable to return fire effectively and trapped by unfavorable winds, the British lost multiple capital ships in a one-sided engagement that shattered the reputation of British naval invincibility in the Pacific.

Faced with these twin military catastrophes and growing political unrest at home, the British government abandoned its ambitions of Asian conquest. King Henrik, turning against the hawkish Whig faction, sought peace to prevent further losses. The conflict concluded with the Treaty of Beijing in 1787, a compromise in which the Ming Empire agreed to recognize the independence of the United Provinces of Mornaea to cut their colonial losses, while Britain was forced to completely withdraw from Siam and Malaya, securing the Ming sphere of influence in Southeast Asia.

Seizing upon the Ming Empire’s distraction with the Hoshihan Revolution, Great Britain opportunistically sought to conquer Southeast Asia, officially declaring war in August 1784 after an initial naval strike. The British strategy relied on a two-pronged assault: the Royal Navy blockaded the Maye Islands to sever Chinese supply lines, while the English Indies Company (EIC) launched a ground invasion into Siam in May 1785. Utilizing a force composed largely of Bengali Sepoys and Burmese warriors, the EIC achieved early, overwhelming success. At the Battle of Pai in July 1785, the British leveraged their superior artillery and disciplined tactics to crush a much larger Siamese army, killing 5,000 and capturing 10,000, which allowed them to push deeper into the region unopposed.

The momentum shifted drastically in January 1786 when the Ming court decided to prioritize the British threat over their rebellious colony, deploying hardened Imperial regulars to reinforce Siam and Malaya. This culminated in the disastrous Battle of Sik in June 1786. The EIC forces, commanded by Henry Ratcliffe, were already suffering from jungle diseases, hostile local populations, and dwindling supplies when they faced a massive Ming-Siamese coalition. Operating under the false hope that naval reinforcements were arriving—unaware they had been destroyed in a typhoon—Ratcliffe ordered a reckless attack. Although the Sepoys initially pushed forward, the Ming utilized their superior artillery numbers to grind down the British lines. A massive evening counter-charge by the Ming and Siamese shattered the EIC formations, resulting in 10,000 British-aligned casualties and forcing a chaotic retreat that erased British territorial gains in the region.

Simultaneously, the Royal Navy suffered a catastrophic and humiliating defeat off the coast of Hainan. In September 1786, a British fleet of thirty-five ships under Jonathan Drake was tasked with intercepting Ming convoys. However, a severe typhoon scattered the fleet and irreparably ruined their gunpowder stores with moisture. When a smaller Ming fleet approached in early October, Drake initially dismissed the threat, only to realize too late that his ships were functionally defenseless. Trapped by stagnant winds at the Battle of Hainan, the British vessels were used as target practice by the Ming cannons. Drake was forced into a desperate retreat, losing several capital ships, including his flagship, and suffering a blow that shattered British naval prestige in the Pacific.

The dual military disasters collapsed public support back in London, sparking fierce debates between the ruling Whig faction under Prime Minister William Pulteney and the anti-interventionist Tories. Confronted with the grim reality of the Asian theater, King Henrik, despite his previous expansionist sympathies, advocated for an immediate end to the hostilities. In May 1787, Britain entered peace negotiations, quickly agreeing to abandon all imperial ambitions in Siam, Annan, and Malaya. The most contentious issue, however, was the Ming demand to revoke the EIC's exclusive, highly lucrative trading lease at the port of Chang-Chou. Desperate to maintain their unique direct-trade access to China, EIC negotiators committed an act of supreme corporate perfidy: they unilaterally promised that the British government itself would pay an indefinite financial indemnity to the Ming Emperor to keep the port open. The Chinese accepted this immense bribe, signing the Treaty of Peking on June 1, 1787, ending the war but secretly saddling the oblivious British Crown with a ruinous debt.