Siam coastline, which they discovered, could easily be clogged up by more numerous Siamese forces. In 1760, the Burmese were forced to spend nearly three months (January–March) to fight their way out of the coastline. This time, they planned a multi-pronged attack from all sides to stretch out the numerically superior Siamese defenses. Secondly, they would start the invasion early to maximize the dry-season campaign period. In the previous war, Alaungpaya started the invasion too late (in late December 1759/early January 1760). When the Burmese finally reached Ayutthaya in mid April, they only had a little over a month left before the rainy season to take the city. This time, they elected to begin the invasion at the height of the rainy season. By starting the invasion early, the Burmese hoped, their armies would be within a striking distance from Ayutthaya at the beginning of the dry season. First wet season offensive (August 1765 – November 1765) Northern front (August 1765) The invasion began on 23 August 1765 (8th waxing of Tawthalin 1127 ME) at the height of the rainy season when the 20,000 strong northern Burmese army (20 regiments and three hundred war-boats) invaded Siam down the Wang River. The southern armies stayed put. The reason for the earlier start of the northern army was that it was much farther away from Ayutthaya than its southern counterparts. Still the strategy did not work as planned. The northern army's advance was greatly slowed by the rainy weather and the "petty chiefs" who put up a fight, forcing Thihapate to storm town after town. Nonetheless, Thihapate fought his way down the Wang, finally taking Tak and Kamphaeng Phet by the end of the rainy season. Southern front (October 1765) Meanwhile, Maha Nawrahta opened the southern front on 23 October 1765 (10th waxing of Tazaungmon 1127 ME) in three directions. He had 20,000 to 30,000 under his command. (The Burmese sources say 30,000 men including 2000 horses and 200 elephants but G E Harvey gives the actual invasion force as 20,000. At least part of the difference could be explained by the rearguard who stayed behind to defend the Tenasserim coast). A small army invaded by the Three Pagodas Pass towards Suphan Buri. Another small army invaded down the Tenasserim coast towards Mergui (Myeik) and Tenasserim (Tanintharyi) town. However, the main thrust of his attack was at Kanchanaburi. His 20,000-strong main southern