If the Inca Empire knew its apogee only shortly before the arrival of the Spaniards, its origin takes root during the XII° century of our era. According to the most accepted legend, the first emperor, Manco Capac, came out of the waters of Lake Titicaca with his wife; he heard the voice of his father, the solar god Inti, telling him to find Q'osqo, the navel of the world, to stick a golden stick in it until it disappeared; there would be the fertile valley where the new civilization that would rule the world would develop. He is the first of the thirteen Inca emperors who will succeed one another until the fall of their domination. The historians, them, estimate indeed that this civilization takes its origin in the area of the Sacred Valley, made powerful by the fertility of its environment, but that it would have especially Amazonian origins.
It is from 1438 that the empire really took off. Following a battle lost in advance against their terrible neighbors, the Chankas, the Inca Viracocha flees, and it is his son who takes again the orders of the kingdom. When he reaches (by miracle) the victory, this one proclaims himself ninth emperor, Pachacutec (in Quechua, "the one who transforms the world"). From that moment on, he begins a lightning conquest with the aim of subduing the neighboring peoples. It was also Pachacutec who undertook the construction of the great works that marked the city of Cusco (he built the Qoricancha and a Palace in the Plaza de Armas), and the agricultural arrangements (river detour, etc.) that allowed the agricultural prosperity of the people. Considered as the Napoleon of the Incas, it is him who imposed the reform towards an organization strong enough to manage a whole empire. His successors, Tupac Yupanqui and Huayna Capac, expanded the empire from southern Colombia to northern Chile.
The internal organization of the Inca Empire was exceptional, because it had succeeded in maintaining a certain imperial order in an immense territory, with very diverse populations, and with very little communication. To ensure the unification of the empire, several strategies were used. First of all, to impose the cult of the Inti solar god without prohibiting the local cults, those adapting thus in order to integrate this Inca cultural variant. Then, the sending of Cusqueen settlers to the annexed territories (with promises of social ascension), and the transfer of the populations to the distant countryside to cultivate, mixed with other peoples, in order to blur the cultural identities. The empire, called Tahuantinsuyo, was divided into four "neighborhoods", meeting in the city of Cusco, the navel of the world. The roads through the mountains and valleys, the famous Inca Trail, were the only communication routes available; relay posts were present at regular intervals along the road. In the heart of this empire, an iron organization was necessary to maintain order. A strong army and a well organized bureaucracy ensured the good functioning of the empire. One of the characteristics of the organization of the empire was the pooling of all goods and the payment of taxes in the form of working time; the redistribution of resources between the different regions and according to needs (natural disasters, etc.). Finally, the absolute weapon of Inca domination was probably the theocratic element that this civilization: the emperor was not ''that'' an emperor; it was a living god, the representative and incarnation of the sun god on earth. Once the people convinced of this state of things, the rebellion was much more complicated to lead, because the Inca empire had succeeded in penetrating in the deepest consciences, in the very cosmovision of these people.
But many omens, predictions and rumors ran on the end of this empire, even before Pizarro and the Spaniards set foot on the South American continent. The rivalry for the succession to the throne of Huayna Capac's two sons, Huascar (from Cusco) and Atahualpa (from Quito, in the north), was already beginning to sow political unrest over the supreme power of the empire. A civil war breaks out, Atahualpa kidnaps his brother, and the submissive peoples take advantage of it to claim their independence, if not greater autonomy: it is in this context of internal chaos that Pizarro arrives. More preoccupied with internal disorder than with the arrival of some strange white-skinned creatures, Atahualpa does not take care, and is captured in Cajamarca by some conquistadors: it is the first Spanish victory. In exchange for his freedom, Atahualpa promises a fabulous ransom of gold and silver; from his prison, he has his brother murdered for fear that he might take back the throne. But once the ransom was given, of course, Atahualpa was not freed, but rather murdered. True living god for the Incas, it is the whole empire which is beheaded; the stampede begins. The arrival in Cusco in 1533 results in lootings and many battles, relatively difficult (only a few tens of Spaniards were present), but Pizarro manages to push back the Incas more and more far in the valley, even obliging them to take refuge in the thick jungle, in Vilcabamba. The Spanish triumph is now complete, and the plundering of the riches can begin in all tranquility.
After these bloody episodes, the economic and social heart of the country turns towards the coast, and towards the City of the Kings, the current Lima, center of the exchanges between Spain and its colonies, and 1st major port of the Spanish Americas. Cusco becomes a simple provincial city, without particular interest, and the colonial houses replaced little by little the imposing Inca walls. The most obvious trace of this: the construction of the church of Santo Domingo on the ceremonial center of the Qoricancha. The revolt of Tupac Amaru II in 1780 took place in the imperial city, symbol of the forgotten Inca inheritance, but the murderous repression on the same Square of Weapon marked just as symbolically the state of domination in Cusco and in all Peru. Apart from that, no event marking came to disturb the quiet course of the things in the city of Cusco, neither more nor less than in the rest of the country. It is, in fact, the ''rediscovery'' of Machu Picchu in 1911 that marks the biggest change for the history of the city.