Question

How did Pachacuti and subsequent Incan rulers construct an Empire?

Answer 1

His conquests where so successful that he is sometimes referred to as "The Napoleon of the Andes." When Pachacuti died in 1471, the empire stretched from Chile to the south and Ecuador to the north also including the modern countries of Peru and Bolivia as well as most of northern Argentina.

Answer 2

Answer:

The official emergence of the Inca Empire happened, according to the historians, with the reign of Sapa Inca (term in Quechua for emperor) Pachacuti. During his reign, the Incas initiated the territorial conquest of the Andean region, process that was continued by other Incas emperors.  The Incas succeeded in building a vastly territorial empire that stretched over 4,000 kilometers, from part of Colombia to northern Chile and Argentina. The conquered peoples were obliged to pay taxes, and the dominated regions were integrated into the empire by means of the construction of roads (the Incas possessed more than 40 thousand kilometers of roads), by order of Sapa Inca, and culturally absorbed with the displacement of Quechua population for these regions.  The great empire of the Incas was called by themselves of Tawantisuyu (the Empire of the four directions, in Quechua)