The Inca Empire (Quechua: Tawantinsuyu, lit. "The Four Regions") was the largest empire in pre-Columbian South America. Its political and administrative structure is considered by most scholars to have been the most developed in the Americas before Christopher Columbus' arrival. The administrative, political and military center of the empire was located in the city of Cusco. The Inca civilization arose from the Peruvian highlands sometime in the early 13th century. Its last stronghold, Vilcabamba, was conquered by the Spanish in 1572.
From 1438 to 1533, the Incas incorporated a large portion of western South America, centered on the Andean Mountains, using conquest and peaceful assimilation, among other methods. At its largest, the empire joined Peru, southwest Ecuador, western and south central Bolivia, northwest Argentina, northern Chile and a small part of southwest Colombia into a state comparable to the historical empires of Eurasia. Many local forms of worship persisted in the empire, most of them concerning local sacred Huacas, but the Inca leadership encouraged the sun worship of Inti – their sun god – and imposed its sovereignty above other cults such as that of Pachamama. The Incas considered their king, the Sapa Inca, to be the "son of the sun."
Quechua was the primary language of the Empire, and was recognized as Peru's second official language in 1969.
Inca Empire in "Eyewear"
While in some timelines, including the one inhabited by Estevánico, the Incan Empire was conquered by Spanish Conquistador Francisco Pizarro, there were others where the Inca survived, drove back Pizarro, and eventually become a dominant global power. In at least one of these, the Inca were at war with the descendants of the unconquered Aztec Empire by the 23rd Century, a war which crossed timelines and time itself.
Estevánico learned of the Inca indirectly from the time traveler Esperanza after the failure of the Pánfilo de Narváez expedition. Estevánico was bitterly amused by the fact that the trip north had been an utter waste, and that a rich empire existed in the south.
Inca Empire in "The Pugnacious Peacemaker"
In the timeline to which Allister Park was transported, the Inca Empire remained uncontacted by Europeans much later than the 16th century. Thus Tawantiinsuuju was one of the most powerful states in Skrelleland. Tawantiinsuuju was ruled by an emperor who was believed by his people to be semi-divine. The people of Tawantiinsuuju were strident in their religious beliefs. In the early 1940s, Maita Kapak was the reigning emperor.
The empire's most important rival was the Emirate of the dar al-Harb, which paralleled the Brazil of Park's world. The Emirate had been founded the Moors of Cordova, and maintained a strong Muslim faith. The two empires fought over territory, but justified their wars through their respective faiths.
A year after he assumed the identity of Ib Scoglund, Park was sent to mediate a peace between the two rivals.
Inca Empire in Through Darkest Europe
It is unclear whether this refers to a never-conquered Inca Empire or a once-occupied culture that preserved itself more successfully than in OTL.
Inca Empire in "Vilcabamba"
On the eve the United States and Canada's final uprising against the Krolp, President Harris Moffatt III's Secretary of Alien Affairs shared with Moffatt the history of the Inca and their last refuge of Vilcabamba. Moffatt recalled that information during the uprising. He sympathized with the Inca, and knew that they'd sympathize with him, for all the good that would do.
- Down in the Bottomlands and Other Places, pg. 218, MMP.
- Ibid., pg. 219-220.
- Ibid., pgs. 215-219, MMP.