Siege of Cusco

For ten months in 1536 and 1537 the Inca ruler Manco Inca Yupanqui besieged the old imperial capital of Cusco, in the Andes of present-day Peru, where a small Spanish garrison under Hernando Pizarro was holding out with thousands of native allies. The siege, which began on 6 May 1536, was the greatest Inca attempt to drive out the conquistadors and restore the Inca Empire. It failed, and Manco withdrew to the remote mountains of Vilcabamba.

The Spanish conquest of the Inca Empire began when Francisco Pizarro seized the Sapa Inca Atahualpa at Cajamarca in November 1532. The Spaniards collected an enormous ransom of gold and silver and then executed him in July 1533, which deepened existing rivalries over the Inca throne and threw the empire into disorder. Pizarro's first puppet emperor, Tupac Hualpa, was soon killed, and after taking Cusco in November 1533 the Spaniards crowned another of Atahualpa's brothers, Manco Inca, a son of the great ruler Huayna Capac. Manco had sided with the invaders against Atahualpa's surviving supporters, but real power lay with the Spaniards, and Pizarro's younger brothers Juan and Gonzalo treated him with contempt. After a failed escape in November 1535 he was imprisoned. Hernando Pizarro released him in January 1536, and on 18 April Manco left Cusco with permission to perform religious ceremonies in the Yucay Valley, promising to return with gold. Instead he met his commanders at Lares and planned a rising.

Manco's army gathered on the hills around Cusco. Estimates of its size vary widely, from about 40,000 to 100,000 or even 200,000 warriors. Inside the city were 190 Spaniards, 80 of them mounted, and several thousand native auxiliaries. On 5 May the Incas occupied the fortress of Sacsayhuamán, which the Spaniards had left empty, giving them high ground where cavalry could not easily operate. The next day they stormed into the city and took most of it, hurling red-hot stones wrapped in cotton and firing burning arrows that set the thatched roofs alight. The Spaniards held out in two large buildings on the main square and made repeated sorties, while the Incas used bolas to bring down their horses.

After about a week the defenders concluded that they must retake the fortress. Following a plan suggested by Pasac, a relative and rival of Manco who had joined the Spaniards, fifty horsemen under Juan Pizarro broke out of the city, pretended to ride away, and then circled back to attack Sacsayhuamán from outside. Juan was struck on the head by a stone and died days later. In a night attack with ladders the Spaniards took the outer terraces; two Inca commanders left to fetch reinforcements, and the towers fell before they could return.

With the fortress lost, the siege became a series of daily skirmishes, paused at each new moon in keeping with Inca religious custom. The Spaniards tried to break their enemies' morale by terror, killing any women they caught and maiming male prisoners by severing their hands. An attack by Hernando Pizarro on Manco's headquarters at Ollantaytambo was beaten off, but foraging raids kept the garrison fed, and a later Inca attempt to surprise Cusco ended in heavy losses when Spanish cavalry discovered and attacked the army at night.

In early March 1537, with his troops discouraged and a Spanish force led by Diego de Almagro approaching from Chile, Manco lifted the siege and retreated to Vilcabamba, where he founded the small Neo-Inca State. Almagro, a rival of the Pizarros, then seized Cusco for himself and imprisoned Hernando and Gonzalo Pizarro. Gonzalo escaped, and Almagro was later defeated at the Battle of Las Salinas, as the conquerors turned on each other.

Our 1530 map shows the Inca Empire on the eve of the conquest, and the 1600 map shows the Andes under the Spanish Empire.