The war began in June. Desperate to consolidate the Chao Phraya valley before the expected dry-season invasion, combined Ayutthaya and Lan Xang forces braved unforgiving rainy season conditions and laid siege to Phitsanulok. But Phitsanulok's reinforced defenses held. In late October/early November, the besiegers retreated to their respective cities before the upcoming invasion. Bayinnaung's five armies (54,600 men, 5300 horses, 530 elephants) arrived at Phitsanulok on 27 November 1568. Reinforced at Phitsanulok, combined armies of 70,000 marched down along the Chao Phraya to Ayutthaya, and laid siege to the city in December 1568.