After the fall of Ava, many independent resistance movements sprang up across a panicked Upper Burma. Yet the Hanthawaddy command left less than 10,000 troops to pacify all of Upper Burma. Alaungpaya, who founded the Konbaung Dynasty, quickly emerged as the main resistance leader, and by taking advantage of Hanthawaddy's low troop levels, went on to conquer all of Upper Burma by the end of 1753. Hanthawaddy belatedly launched a full invasion in 1754 but it faltered. Konbaung forces invaded Lower Burma in January 1755, capturing the Irrawaddy delta and Dagon  by May. The French defended Syriam held out for another 14 months but eventually fell in July 1756, ending French involvement in the war. The fall of the 17-year-old southern kingdom soon followed in May 1757 when Pegu was sacked. Lan Na, Martaban, Tavoy and Sandoway all submitted after Pegu's fall.. How many months did it take Konbaung forces to invade Lower Burma and capture Irrawaddy delta and Dagon?