King Taksin of Siam was not reconciled to the ascendant position gained by the Vietnamese in Cambodia when Ang Eng was placed on the throne with Mou as regent in 1779. In 1780, he took an accusation of conspiracy as reason to kill fifty-three high-ranking Vietnamese refugees in Siam, including Mac Thien Tu and a son of Nguyen Phuc Khoat. During the winter dry season of 1781–1782, he sent General Chakri to attack the Vietnamese and their Khmer allies in Cambodia. In the midst of this campaign, Taksin was deposed in a coup. Chakri met with the Vietnamese generals and negotiated an end to hostilities, then hastened back to Siam where he was crowned king. This was the beginning of an alliance between Chakri and Nguyen Phuc Anh that would continue for twenty years, until the end of the Vietnamese wars. Shortly after the return of the Vietnamese army from Cambodia in spring of 1782, Nguyen Nhac and Nguyen Hue arrived with several hundred ships and thousands of men at the Can Gio estuary, the main entrance to the Sai Gon and Dong Nai Rivers. As the Tay Son forces fought their way upriver their progress was reportedly resisted the longest by a European-style ship commanded by a Frenchman whose name was recorded by the Vietnamese as Man Hoe (Manuel). This man was a French adventurer who had been introduced to Nguyen Phuc Anh by Pierre Pigneau. He perished with his ship, and the Tay Son took Saigon. As Tay Son armies moved against Nguyen Phuc Anh at My Tho, Nguyen Phuc armies from the northern coast arrived and attacked the Tay Son from the other direction. During the battle that ensued, troops under the command of generals from the Chinese community in Cholon managed to kill a kinsman of Nguyen Nhac, which so enraged him that he slaughtered some ten thousand members of the Chinese community – men, women, and children – filling the rivers with their corpses. Nguyen Phuc Anh was soon forced to flee to Phu Quoc Island, off the coast of Ha Tien, where he sent a request to Chakri of Siam for help. Nguyen Nhac and Nguyen Hue returned to Qui Nhon at mid summer. In the autumn, Nguyen Phuc Anh fought his way back to retake Saigon. For six months he feverishly prepared for the expected Tay Son counterattack while also mobil- izing a Khmer army from Cambodia. Nguyen Hue and Nguyen Lu returned to the offensive in spring 1783, arriving at Gia Dinh with a large seaborne army. Nguyen Phuc Anh’s allied Khmer–Viet armies were defeated, and he eventually found refuge again on Phu Quoc Island. Nguyen Phuc Anh’s appeal to Chakri was answered in autumn 1783 with Siamese armies moving through Cambodia to attack the Tay Son. The pro- Vietnamese regent, Mou, was killed by his enemies and replaced by a pro- Siamese regent, Ben, who ceded Cambodia’s western provinces to Siam and sent the young king, Ang Eng, to Bangkok for safekeeping. A younger brother of Mou named Ten mobilized his followers and joined the Tay Son resistance against the advance of the Siamese. A second Siamese force arrived by sea at Ha Tien. Tay Son and Siamese armies confronted each other and fought several battles in the region of Sa Dec until the Siamese were forced to withdraw in late 1783. The Tay Son advanced to Phnom Penh where they placed Ten in power. The pro-Vietnamese Khmer had found new patrons in the Tay Son. Meanwhile, Siamese forces remained in Cambodia to support Ben at Oudong. Nguyen Phuc Anh and what survived of his entourage found refuge at Chakri’s court in the new Siamese capital of Bangkok. In mid 1784 a large Siamese expedition set out against the Tay Son both by land and by sea. The Siamese defeated the Tay Son at Sa Dec and continued downriver toward My Tho, the gateway to Saigon. Nguyen Phuc Anh com- plained to the Siamese generals that their men were plundering the local people and giving him a bad name. The Siamese generals seem not to have paid him any heed, nor to have availed themselves of his local knowledge. Ignorant of tidal currents in the lower Mekong, they fell into a Tay Son ambush as they prepared to attack My Tho by river. In the last lunar month of the year, at what became known as the Battle of Rach Gam–Xoai Mut, Nguyen Hue defeated the Siamese expedition and sent it fleeing back the way it had come. Nguyen Phuc Anh was once again reduced to being an offshore wanderer. By late spring 1785 he had found refuge in Siam. He built a settlement outside of Bangkok and rallied his scattered followers. Within a few months several thousand men had gathered under his command. For the next year he served as a loyal ally of Chakri while sending spies to stay informed of conditions in Gia Dinh. He led his army against Burmese invaders, reportedly making use of “fire-spewing pipes.” When Malay invaders threatened the Siamese south, he sent men to help repulse them. After two years of exile in Siam, a falling out among the Tay Son leaders gave him the opportunity he needed to return to Gia Dinh. During 1785, the north was plagued with continual rain, insect infestations, pirates ravaging the coast of Yen Quang (modern Quang Ninh), soaring rice prices, famine, and starvation. At Ke Cho, Trinh Khai watched helplessly as the soldiers from Thanh Hoa and Nghe An strutted around the capital and intimi- dated government officials. In Thuan Hoa, the Trinh governor was uninterested in military matters. He spent his time building a personal fortune from commer- cial ventures while letting border defense lapse. After Tay Son forces had gained control of Gia Dinh and expelled Nguyen Phuc Anh into Siamese exile, and after news from the north indicated that the Trinh were in trouble, Nguyen Nhac decided to act on Nguyen Huu Chinh’s advice to seize Thuan Hoa and thereby reassemble the old Nguyen Phuc domain under his hand. In summer of 1786, Nguyen Nhac sent Nguyen Hue into Thuan Hoa. Nguyen Huu Chinh and Vo Van Nham commanded land forces and Nguyen Lu commanded naval forces. Treachery among the Trinh generals assisted their advance, and Thuan Hoa was taken with relative ease. Nguyen Hue then made a decision that would have far-reaching consequences. Nguyen Huu Chinh and other northerners were urging him to march on Ke Cho, pointing out that government in the north was in disarray. Without consulting his elder brother, Nguyen Hue left Nguyen Lu at Phu Xuan and continued north, announcing that he intended “to exterminate the Trinh and restore the Le.” Meeting little resistance along the way, he arrived at Ke Cho in less than a month. Trinh Khai fled and took his own life as the southerners suppressed the disorderly soldiers in the capital. Nguyen Hue went to see the king. Le Duy Dieu was known as a kindhearted and even-tempered man. He was now 70 years old and in poor health. He endeavored to placate Nguyen Hue by giving him one of his daughters in marriage. And then he suddenly died. Le Duy Khiem, the 21-year-old crown prince, was raised to the throne. Shortly after, as Le Duy Dieu was being buried in Thanh Hoa, Nguyen Nhac appeared, angry about his younger brother’s insubordinate northern adventure. Nguyen Nhac considered involvement in northern affairs to be a great mistake and saw no value in the north except as a place to plunder, and plundering is what he and his men proceeded to do. But most of all, Nguyen Nhac did not like Nguyen Hue acting on his own initiative. For his part, Nguyen Hue was begin- ning to see beyond his brother’s provincial perspective and to chafe at his brother’s efforts to keep him in line. He also understood that the north was a difficult place to govern and that he needed a base in the south. The two brothers quarreled, then raced back south to mobilize their follow- ers and test their clashing ambitions on the battlefield. Nguyen Nhac called on his army in Gia Dinh to march north to assist him. Nguyen Hue ambushed it in Phu Yen and forced it to surrender. The two brothers fought for several months in their home province of Binh Dinh. Nguyen Hue besieged Nguyen Nhac in his capital of Cha Ban, but the brothers had exhausted each other, and, in early 1787, negotiated a peace, partitioning the Tay Son realm. Nguyen Hue received Thuan Hoa and northern Quang Nam. He went to Phu Xuan and proclaimed himself “the king that pacifies the north.” Nguyen Nhac proclaimed himself “emperor of the center” at Cha Ban and sent Nguyen Lu to hold Gia Dinh. The fighting among the Tay Son brothers gave Nguyen Phuc Anh the oppor- tunity he had been waiting for. By early 1787, his agents were already active along the coasts of Ha Tien, Rach Gia, and Ca Mau. In early autumn, he and his men slipped away from Siam by sea. He established himself on the island of Hon Tre off the Rach Gia coast. The Tay Son governor of the lands along the western Vietnamese coast submitted to him, as did a Qing pirate on Con Dao Island. Within weeks he had gained the submission of all the territory south of the lower branch of the Mekong. A premature seaborne attack up the Sai Gon River failed, but it frightened Nguyen Lu into fleeing back to Qui Nhon, where he died shortly after. However, several Tay Son generals remained at their posts and continued to resist. Ten, the Khmer ally of the Tay Son, joined them against Nguyen Phuc Anh. Ten’s enemy, the pro-Siamese Ben, came into the fray on Nguyen Phuc Anh’s side. By the end of the year, Nguyen Phuc Anh had captured Ten and sent him to Siam. In the spring of 1788, Nguyen Phuc Anh’s battlefield victories were gaining momentum and Tay Son units began to surrender to him. By summer, Nguyen Phuc Anh was organizing law and tax regimes in the areas under his control, and by autumn he had retaken Saigon and was busy setting up a new structure of government. At that time, Nguyen Hue was preparing another major initiative in the north, where his ambitions were focused. This, with the shrinking of Nguyen Nhac’s sphere of action to his provincial domain and Nguyen Lu’s incapacity, had opened the way for Nguyen Phuc Anh’s return from Siam.