sentences:  At that time, Võ Tánh's army, called the Kiến Hòa army, grew to a force of 10,000 men.Meanwhile, Nguyễn Ánh was badly defeated at the Battle of Rạch Gầm-Xoài Mút and fled to Siam which made the Kiến Hòa army the only rival of the Tây Sơn in the Gia Định region.In 1787, Nguyễn Ánh returned to Gia Định from Siam and began attacking the Tây Sơn.