His cousin Diego Tupac Amaru was also unsuccessful to the eastward. His division was detached from the main army at Checacupe, where he crossed some mountainous country, and again descended into the valley of the Vilcamayu, following the course of the river until he encountered the forces under the command of the Marquis of Rocafuerte, consisting of the levies of Pumacagua, Cacique of Chinchero, and those of the Caciques of Maras and Huayllabamba. An engagement took place at Huaran, on the banks of the river, near Calca, when Diego was defeated, many of his Indians being drowned in the river; and he again suffered defeat at Yucay on December 23rd. The Indian chief then left the valley of the Vilcamayu, crossed a range of mountains, and laid siege to the town of Paucartambo, on the banks of the rapid river of the same name, while his videttes hovered over the heights above the Vilcamayu valley, threatening the towns of Calca, Pissac, and Taray. Don José Antonio Vivar was sent to occupy the bridge at Urubamba, and watch the movements of the Indians. Paucartambo, and a strong fort built on a rocky height on the opposite side of the river, were desperately defended by the Spaniards under Don Lorenzo Lechuga, who had fortified and garrisoned the place. Astete was sent across the bridge at Urubamba, with 400 men, to relieve it; they had several encounters with the Indians on the march, and on reaching the besieged town they found that Lechuga had expended all his ammunition; but the besieging force, under Diego Tupac Amaru, fell back towards Tinta, on the approach of Astete, on the 18th of January, 1781. Having re-organized his army at Tinta, the Inca, accompanied by his cousin Diego, made another attack upon Paucartambo on the 11th of February; but, after several fruitless assaults, the Indian army finally retreated to Tinta on the 14th.[222] Tupac Amaru had now assembled a force of 60,000 men in and around Tinta; but they were wholly undisciplined, and only a few hundreds were armed with muskets. All the caciques in Peru, with the exception of sixteen,[223] had, however, declared in favour of the Inca; and the whole Indian and mestizo population, except the _ayllus_ or tribes of the sixteen Hispanicized caciques, longed earnestly for the success of this truly national insurrection. After the retreat from Paucartambo in February, the Inca occupied himself in strengthening his position round Tinta, and in visiting the distant provinces of Chuquibamba and Cotabambas, while one Isidro Mamani, an Indian of ferocious character, born at Pomata, on the banks of lake Titicaca, Pedro Vargas, and Andres Ingaricona, held the open country in the Collao.