Oyo

Oyo State, in south-western Nigeria, is the successor territory of the historic Oyo Empire, one of the most powerful Yoruba states of the pre-colonial era, and it retains that empire's traditional ruler, the Alaafin of Oyo, as one of the foremost Yoruba monarchs. Its capital, Ibadan, grew in the nineteenth century from a war camp into one of the largest indigenous cities in sub-Saharan Africa and remains a major commercial and educational centre, home to the University of Ibadan, Nigeria's oldest university. Oyo State in its current form was created in 1976, with subsequent boundary changes leading to the creation of Osun State from it in 1991. The state's nickname, the "Pace Setter State", reflects its historic role in education and public administration in the region.

The Oyo Empire emerged around the fifteenth century in the savanna north of the forest belt and grew, particularly from the seventeenth to early nineteenth centuries, into a dominant Yoruba military and trading power under the Alaafin, ruling through a council of chiefs known as the Oyo Mesi. Internal political crises, the rise of the warlord Afonja at Ilorin and his alliance with the Fulani cleric Alimi in the 1810s, and subsequent Fulani jihad pressure contributed to the empire's decline and the loss of Ilorin to what became a Fulani emirate. The Oyo capital was later re-established further south at present-day Oyo town. Ibadan rose during the nineteenth-century Yoruba civil wars as a war camp that developed into a powerful city-state in its own right, later becoming the administrative centre of the Western Region under British rule. Oyo State was created in 1976 from the old Western State, and in 1991 Osun State was split from it.

Oyo State lies inland in south-western Nigeria, bordered by Kwara State to the north, Osun State to the east, Ogun State to the south, and the Republic of Benin to the west. The terrain transitions from tropical rainforest in the south around Ibadan to derived and Guinea savanna in the north towards the Kwara border, reflecting the state's position at the ecological boundary between forest and savanna zones. Rivers including the Ogun and Oyan drain the state, with the Oyan River dammed to form a reservoir used for irrigation and water supply. The climate is tropical, with distinct wet and dry seasons, and the northern parts of the state experience more pronounced dry-season harmattan conditions than the humid south.

Ibadan has long been a major centre of trade, transport and light industry in south-western Nigeria, benefiting from its position on road and rail routes linking Lagos to the north. Agriculture remains significant across the state, with cocoa, cassava, maize, yam and oil palm widely cultivated, and Oyo State has historically been one of Nigeria's cocoa-producing areas alongside Ondo and Osun. The state hosts several tertiary institutions, including the University of Ibadan and Ladoke Akintola University of Technology, supporting an education and research sector, alongside agricultural research institutes such as the International Institute of Tropical Agriculture. Markets in Ibadan, including Bodija and Dugbe, serve as major regional trading points for food and manufactured goods.