The ruler associated with the Temple of the Sun in Inca history is Pachacuti, who reigned during the 15th century. He is renowned for significant expansions of the Inca Empire and for the establishment of Cusco as the capital. Pachacuti transformed the kingdom into a powerful empire and is often credited with substantial architectural innovations, including the construction of the Temple of the Sun, an important religious site dedicated to Inti, the sun god. This temple featured elaborate designs and was central to Inca cosmology and society, reflecting the empire's reverence for the sun and its vital role in agrarian life and rituals.