Burmese–Siamese War (1662–64)

First invasion

Fearing a possible weakening of influence in the northern vassal states following the successful the Ming Chinese invasion of Ava in 1660 to capture Zhu Youlang, King Narai mounted an expedition to bring Lan Na under the direct control of Ayutthya kingdom. Although the expedition was successful in taking control of Lampang and other smaller cities. In March 1662 he got Martaban to switch sides, and occupied upper Tenasserim coast. Fortunately for the Burmese, their troubles with the Ming were over. Their land and naval units recaptured Martaban and Tavoy by December 1662. They followed up on the retreating Siamese but were driven back near Kanchanaburi with heavy losses.

Second invasion

A second expedition had to be conducted to bring Lan Na under control again. The Siamese army invaded Chiang Mai, catching the Burmese command completely off guard. The Siamese captured Chiang Mai on 10 February 1663, and drove back Burmese forces that arrived belatedly at Sai Yok. In November 1663, the Siamese then led an army of 60,000 in an invasion of Burma, capturing Martaban, Moulmein, Syriam, Rangoon, Pegu, and then laid siege to Pagan in 1664. Burmese defences withstood several Siamese onslaughts until May 1664 before the rainy season arrived, after "causing many casualties in dead and wounded and capturing many prisoners of war", the Siamese retreated.

Meanwhile, the Siamese garrison at Chiang Mai was holed up in a deserted city, and its troops were constantly ambushed by resistance forces whenever they ventured out of the city. In late November 1664, the Siamese evacuated Chiang Mai, and returned.

Aftermath

This was the last major war between the two kingdoms until 1760 although they traded small raids in 1675–1676, and in 1700–1701.