Who greatly expanded the Inca Empire and how did he do it?

Pachacuti, the ninth Sapa Inca of the Inca Empire, greatly expanded its territory in the 15th century. He accomplished this through a combination of military conquest, strategic alliances, and administrative reforms. Pachacuti reorganized the empire's political structure, integrating conquered peoples and promoting the Inca religion and culture, which helped to consolidate his power and facilitate further expansion. His successful campaigns extended the empire from present-day southern Colombia to central Chile.