There is no doubt that the great majority of these stupendous monuments of a former age were not the actual handiwork of the Incas.  It is now considered practically certain that these Incas, themselves enlightened and progressive, were merely using the immense structures both of material masonry and of theoretical civilization left behind by a previous race whom the Children of the Sun had conquered and subdued.  It is not improbable that this race was that of the Aymaras; in any case it is certain that the Empire of the Incas was not of old standing, and that they had not occupied the countries they held for more than a few hundred years before the advent of the Spaniards.

[Illustration:  Manco Capac, the legendary founder of the Inca empire, collecting his people for the work of building the city of Cuzco.]

The Incas possessed a very definite theory concerning the origin of their tribe.  Sun-worshippers, they loved to think that they themselves were descended from a chance fragment of that terrible and blazing luminary.  Thus their religion had it that the first Inca was a child of the Sun who came down to earth in company with his sister-wife.  The spot they chose was an island on Lake Titicaca.  Here they alighted in all their brilliancy, and the Indians of the neighbourhood gathered about them and fell at their feet, receiving them as rulers with infinite gratitude.  This first Inca, whatever may have been his real origin, was undoubtedly known as Manco-Capac, and his sister-wife was known as Mama-Oclle.  Manco-Capac represented the first of a dynasty of thirteen Emperors, the last of whom suffered at the hands of Pizarro.  Until the end of their race these Incas had retained a considerable degree of the sacred character with which tradition had invested the first of their line.  The person of the Emperor was, indeed, worshipped as a demi-god.  Justified by tradition, he had the privilege of marrying his sister.  It is curious to remark here the resemblance in the customs of the Incas and the Pharaos.

An alternative theory of the origin of the Inca race, although not authoritative, is worthy of note.  W.B.  Stevenson, in a work published in 1825, states that a curious tradition was related to him by the Indians in various parts of Peru.  According to this the progenitor of the royal Incas was an Englishman who was found stranded on the coast by a certain cacique of the name of Cocapac!  The cacique took the stranger to his home, and the Englishman married the chieftain’s daughter.  From this union sprang a boy, Ingasman Cocapac, and a girl, Mama-Oclle.  These were both of fair complexion and hair.