<P> Atahualpa offered the Spaniards enough gold to fill the room he was imprisoned in and twice that amount of silver . The Inca fulfilled this ransom, but Pizarro deceived them, refusing to release the Inca afterwards . During Atahualpa's imprisonment Huáscar was assassinated elsewhere . The Spaniards maintained that this was at Atahualpa's orders; this was used as one of the charges against Atahualpa when the Spaniards finally executed him, in August 1533 . </P> <P> Although "defeat" often implies an unwanted loss in battle, much of the Inca elite "actually welcomed the Spanish invaders as liberators and willingly settled down with them to share rule of Andean farmers and miners ." </P> <P> The Spanish installed Atahualpa's brother Manco Inca Yupanqui in power; for some time Manco cooperated with the Spanish while they fought to put down resistance in the north . Meanwhile, an associate of Pizarro, Diego de Almagro, attempted to claim Cusco . Manco tried to use this intra-Spanish feud to his advantage, recapturing Cusco in 1536, but the Spanish retook the city afterwards . Manco Inca then retreated to the mountains of Vilcabamba and established the small Neo-Inca State, where he and his successors ruled for another 36 years, sometimes raiding the Spanish or inciting revolts against them . In 1572 the last Inca stronghold was conquered and the last ruler, Túpac Amaru, Manco's son, was captured and executed . This ended resistance to the Spanish conquest under the political authority of the Inca state . </P> <P> After the fall of the Inca Empire many aspects of Inca culture were systematically destroyed, including their sophisticated farming system, known as the vertical archipelago model of agriculture . Spanish colonial officials used the Inca mita corvée labor system for colonial aims, sometimes brutally . One member of each family was forced to work in the gold and silver mines, the foremost of which was the titanic silver mine at Potosí . When a family member died, which would usually happen within a year or two, the family was required to send a replacement . </P>

When was the inca civilization at its peak