The nobility of Peru consisted of two orders, the first and by far the most important of which was that of the Incas, who, boasting a common descent with their sovereign, lived, as it were, in the reflected light of his glory.  As the Peruvian monarchs availed themselves of the right of polygamy to a very liberal extent, leaving behind them families of one or even two hundred children, the nobles of the royal blood, though acknowledging only their descendants in the male line, came in the course of years to be very numerous. They were divided into different lineages, each of which traced its pedigree to a different member of the royal dynasty, though all terminated in the divine founder of the empire. 

They were distinguished by many exclusive and very important privileges; they wore a peculiar dress; spoke a dialect peculiar to themselves; and had the choicest portion of the public domain assigned for their support.  Most of them lived at court near the prince, sharing in his counsels, dining at his board, or supplied from his table.  They alone were admissible to the great offices in the priesthood.  They were invested with the command of armies, and of distant garrisons, were placed over the provinces, and, in short, filled every station of high trust. Even the laws, severe in their general tenor, seem not to have been framed with reference to them; and the people, investing the whole order with a portion of the sacred character which belonged to the sovereign, held that an Inca noble was incapable of crime. 

The other order of nobility was the Curacas, the caciques of the conquered nations, or their descendants.  They were usually continued by the government in their places, though they were required to visit the capital occasionally, and to allow their sons to be educated there as the pledges of their loyalty.  It is not easy to define the nature or extent of their privileges.  They were possessed of more or less power, according to the extent of their patrimony, and the number of their vassals.  Their authority was usually transmitted from father to son, though sometimes the people chose the successor. They did not occupy the highest posts of state, or those nearest the person of the sovereign, like the nobles of the blood.  Their authority seems to have been usually local, and always in subordination to the territorial jurisdiction of the great provincial governors, who were taken from the Incas. 

It was the Inca nobility, indeed, who constituted the real strength of the Peruvian monarchy.  Distinguished by a peculiar dress and insignia, as well as by language and blood, from the rest of the community, they were never confounded with the other tribes and nations who were incorporated into the great Peruvian monarchy.  After the lapse of centuries, they still retained their individuality as a peculiar people.  They were to the conquered races of the country what the Romans were to the barbarous hordes of the Empire, or the Normans to the ancient inhabitants of the British Isles.  Clustering around the throne, they formed an invincible phalanx, to shield it alike from secret conspiracy and open insurrection. Though living chiefly in the capital, they were also distributed throughout the country in all its high stations and strong military posts, thus establishing lines of communication with the court, which enabled the sovereign to act simultaneously and with effect on the most distant quarters of his empire.  They possessed, moreover, an intellectual preeminence, which, no less than their station, gave them authority with the people.  Indeed, it may be said to have been the principal foundation of their authority.  The crania of the Inca race show a decided superiority over the other races of the land in intellectual power; and it cannot be denied that it was the fountain of that peculiar civilization and social polity, which raised the Peruvian monarchy above every other state in South America.