Ìsèdó (Ìsẹ̀dó or Ìsẹ̀dó-Olúmọ̀) is an ancient Igbomina kingdom in northeastern Yorubaland of Nigeria. Ìsẹ̀dó was founded as a new city-state several centuries ago (between 1250 to 1400) by Ọba'lumọ, a Prince of the ancient Oba civilization (whose name or appellation is contracted from "Ọba Olumọ" meaning "knowledgeable king", or "king of the lords of knowledge"). Ìsẹ̀dó is fully known and called "Ìsẹ̀dó-Olúmọ̀" using its founder-king's name as an identifier suffix. Ọba'lumọ, emigrated from the ancient Ọ̀bà civilization in northeastern Yorubaland. Foundation and development Obalumo, a prince of the Oba civilization, and a veteran hunter and warrior, founded Ìsẹ̀dó, his new city-state in one of the areas of his frequent hunting expeditions. Recent archaeological research results (and published works of oral history experts, anthropologists and archaeologists of the Arizona State University, USA and the University of Ibadan, Nigeria); of the region's contemporary and later settlements suggest that Ìsẹ̀dó was founded between the 10th and the 12th centuries by Ọ̀bà refugees probably fleeing from both internal dissension in their Òbà kingdom as well as the cyclic conflicts of their Ọ̀bà kingdom with the neighbouring kingdoms, perhaps including the Nupe to the north. At its zenith towards the end of the 15th century, Ìsèdó had grown into a city-state of 13 clans, some of which were later "consolidants" into the Obalumo's kingdom at Ìsèdó and were not of the ancient Oba origin. New arrivals Some oral-historians indicate that at the request of an arriving faction from Ila-Yara, the city-state founded by Òràngún, Oduduwa's fourth son, the region's king, Ọba'lúmọ̀ gave land-grants to the new arrivals at a location thought to be sufficiently distant from Ìsẹ̀dó's location. Another version of the oral history, which seems more reliable, indicates that the land-grant occurred a few centuries later, when the faction of the younger of two quarreling princes arrived in the vicinity of the Ọba'lúmọ̀'s Ìsèdó kingdom, from the schism at their old kingdom at Ìlá Yàrà. Arutu Oluokun, the younger of the feuding princes, founded a settlement at the Ila-Magbon, but the new kingdom moved within a short time to found another city called Ila-Odo closer to Isedo, which subsists as the modern Ìlá Òràngún. Consolidation and accommodation An annual celebration called "Ìmárúgbó" (or "Òkùnrìn") festival was instituted between the two city-states during which the King Ọ̀ràngún leaves his palace with his chiefs to pay a day-long homage to his primogenitor, the King Ọba'lúmọ̀