Who was the Inca Emperor when Machu Picchu was built?

The Inca Emperor during the construction of Machu Picchu was Pachacuti Inca Yupanqui. He is credited with expanding and transforming the Inca Empire into a powerful and centralized state. Machu Picchu was built as a royal estate for Pachacuti Inca Yupanqui around the mid-15th century.