The Siege That Almost Was: 1536 and the Spanish Peru That Almost Did Not Happen

The standard short history of the Spanish conquest of Peru runs: Pizarro landed in 1532, captured Atahualpa at Cajamarca, ransomed and executed him, marched on Cusco, took it in November 1533, and the Inca state was finished. The chronology is correct in dates. Everything else about it is a compression that flatters the conquistadors.

The siege of Cusco in 1536 is what the compression leaves out. It nearly reversed the conquest. It is the central military event in the four decades during which the outcome of Spanish Peru was an open question, and it is the reason Sacsayhuaman, the colossal three-tier fortress on the hill above Cusco, is the climax stop on the Inca Empire tour.

What had happened by 1536

Pizarro's men entered Cusco in November 1533. They installed a puppet emperor, Manco Inca, son of Huayna Capac and half-brother of the executed Atahualpa. Manco was seventeen or eighteen years old. The Spanish believed they had an ally; in practice, they had a captive ceremonial figure. Cusco was looted of the gold and silver they could carry. Qorikancha was stripped within months. The Inca civil war had already destabilized the imperial bureaucracy; the new Spanish administration sat on top of an empire still in shock.

In the two years that followed, the conquistadors began to fight each other. Pizarro and his partner Diego de Almagro split the spoils of the conquest unevenly. Almagro took a force south into Chile in 1535 looking for richer territory and found mostly cold weather and Mapuche resistance. By late 1535 he was returning toward Cusco. Pizarro's brother Hernando had taken charge of the city, treated Manco with open contempt, and demanded gold the puppet emperor could not produce. Manco, by his own account preserved in the later Inca chronicles of Titu Cusi Yupanqui, decided the alliance was over.

In April 1536, Manco escaped Cusco under pretext of conducting a religious ceremony in the Yucay valley. He returned with an army.

The army

Counts of the Inca force are unreliable in the Spanish chronicles. Pedro Pizarro, the conquistador chronicler, said one hundred thousand. Other accounts said two hundred thousand. The honest historical answer is somewhere in that range: tens of thousands of trained Inca soldiers, supplied with food and weapons from the Sacred Valley to the north and the highland communities loyal to the Inca dynasty. Manco's coalition was a real military force, with discipline, leadership, and supply lines.

The Spanish garrison in Cusco numbered approximately one hundred and ninety men. Most were on foot. About eighty had horses. Hernando, Juan, and Gonzalo Pizarro were the senior commanders, along with various lesser captains. They had Toledo steel, crossbows, and a handful of harquebuses. They were vastly outnumbered.

In May 1536, the Inca army occupied the hills above Cusco. The siege began.

What happened in Cusco

The Inca strategy was sound. Cut off food and water; isolate the Spanish garrison inside the city; force them to either starve or break out into open battle on Inca-chosen terrain. Manco's forces burned the thatch roofs of Cusco by shooting fire-tipped arrows from the surrounding heights. The city center became unlivable for the defenders, who retreated into a few stone structures near the Plaza de Armas. The Spanish horses, the single greatest tactical advantage in open battle, were almost useless inside a burning city.

For weeks, the defenders held by counter-attacking at night and during gaps in the Inca rotation. Andean armies of the period traditionally returned to their home districts during planting and harvest seasons, both for the agricultural work and because supply was difficult over long campaigns. Manco's forces could not sustain unbroken siege intensity for an unlimited time. The Spanish, paradoxically, could last longer in a static defense, because their numbers were so small that the urban food stores at hand could feed them for months.

The pivot point was Sacsayhuaman.

What happened at Sacsayhuaman

Sacsayhuaman is the great Inca complex on the hill immediately north of Cusco. The three zigzag walls, each up to four hundred meters long and built from stones some of which weigh over a hundred and twenty tons, were begun by Pachacutec around the 1450s and continued by his successors. The site has been read variously as a ceremonial center, a fortress, a state granary, and a royal estate. The truth is probably some combination. What it became in May 1536 is the command position of the Inca siege of Cusco. Manco's forces fortified it. The siege of the city below could be directed from above.

For the Spanish, this was intolerable. As long as Manco held Sacsayhuaman, the high ground was Inca and the siege would not end. Hernando Pizarro decided that the city could only be saved by retaking the fortress. He left his brother Juan in charge of the city defenses and led a cavalry breakout north and uphill toward Sacsayhuaman.

The Inca defenders held the parapets. Juan Pizarro was killed in the assault, struck on the head by a stone from the walls. The Spanish broke through the outer terraces and entered the inner enclosure. The Inca commander Cahuide, in some accounts named Titu Cusi Huallpa, fought from one of the three towers and, when the Spanish forced his position, jumped from the highest tower rather than surrender. The Spanish took Sacsayhuaman after several days of fighting. The siege of Cusco was not immediately broken, but the strategic balance had shifted.

What the siege almost did

The point that the standard short history skips is that Spanish Peru was not assured even after the Spanish retook Sacsayhuaman. Manco's forces continued the siege of Cusco into early 1537. A parallel Inca army besieged the Spanish settlement at Lima for several weeks in August 1536. Relief forces from Lima trying to reach Cusco were ambushed in the highland passes; some columns were wiped out. Almagro returned from Chile only in April 1537 and helped break the siege, but his arrival also triggered a Spanish civil war that almost destroyed the colonial administration from within.

Through 1537 and into 1538, Manco continued to lead resistance from the Yucay valley and then withdrew into the Vilcabamba region, the steep tropical forest country northwest of Cusco. He established a Neo-Inca state at Vilcabamba that maintained an independent indigenous government, separate Inca religious practice, and ongoing armed resistance against the colonial administration. The Neo-Inca state at Vilcabamba lasted thirty-six years. Manco was assassinated there in 1544 by Spanish renegades he had sheltered. His successors continued the resistance until the last Neo-Inca emperor, Tupac Amaru, was captured by Spanish forces under Viceroy Francisco de Toledo and executed in the Plaza de Armas of Cusco in 1572.

The line from the 1536 siege to the 1572 execution is the line of the resistance war. It lasted thirty-six years. It is not a footnote.

Why we forget

There are several reasons the 1536 siege is not the central story of the Spanish conquest in the standard textbook.

First, it failed. The Inca army did not retake Cusco. The Neo-Inca state at Vilcabamba was eventually crushed. The colonial administration eventually consolidated. A failed military campaign is harder to teach than a successful one because the narrative does not arrive at a clean outcome.

Second, the Spanish chroniclers had reason to minimize it. The conquistador self-presentation depended on a brisk and decisive conquest, not on a ten-month siege in which the garrison was outnumbered roughly a thousand to one and nearly lost. Pedro Pizarro and other eyewitnesses left detailed accounts, but the digested colonial history that became standard in the eighteenth and nineteenth centuries downplayed them.

Third, the central documents of the Inca side were oral. The Quechua-language histories preserved in the chronicles of Garcilaso de la Vega, Felipe Guaman Poma de Ayala, and Titu Cusi Yupanqui give the resistance account, but these texts circulated less and were taken less seriously by metropolitan historians until the twentieth century.

The result is a popular history of the conquest in which 1533 is the final date. The Inca Empire tour's stop at Sacsayhuaman is partly an argument with that history.

What you see today

Sacsayhuaman remains the largest Inca structure visible above ground. The three zigzag walls are still there. The towers were dismantled by the Spanish in the late sixteenth century for building stone, including stone hauled downhill to face the cathedral on the Plaza de Armas. The base courses of the walls, the megalithic ones with the hundred-and-twenty-ton blocks, were too heavy to move and so were left.

Walk along the lowest tier and look at the fit of the joints. The stones at Sacsayhuaman are larger and more irregular than those in the historic-center walls, but the technique is the same. Multiple-plane joints. No mortar. The wall has held its line for almost six centuries. The 1950 earthquake that destroyed parts of the cathedral did not move it. The 2007 earthquake did not move it.

The wall is also the surface against which the 1536 siege was fought. Spanish horses came up the ramp where the modern path now climbs. Inca defenders held the parapets where you can stand today. Juan Pizarro died here. Cahuide jumped from one of the towers that used to stand on the upper terrace.

Walk slowly. The siege was not in a textbook; it was on this hill. The Spanish nearly lost. Spanish Peru is a contingent fact. The wall remembers.