Nasarawa State is a state in the North Central region of Nigeria, bordered to the east by the states of Taraba and Plateau, to the north by Kaduna State, to the south by the states of Kogi and Benue, and to the west by the Federal Capital Territory. Named for the historic Nasarawa Emirate, the state was formed from the west of Plateau State on 1 October 1996. The state has thirteen local government areas and its capital is Lafia, located in the east of the state, while a key economic centre of the state is the Karu Urban Area—suburbs of Abuja—along the western border with the FCT. Of the 36 states of Nigeria, Nasarawa is the fifteenth largest in area and second least populous with an estimated population of about 2.5 million as of 2016. Geographically, the state is mostly within the tropical Guinean forest–savanna mosaic ecoregion. Important geographic features include the River Benue forming much of Nasarawa State's southern borders and the state's far northeast containing a small part of the Jos Plateau. Nasarawa State is inhabited by various ethnic groups, including the Koro and Yeskwa in the far northwest; the Kofyar in the far northeast; the Eggon, Gwandara, Mada, Ninzo, and Nungu in the north; the Alago, Goemai, and Megili in the east; Eloyi (Ajiri/Afo) in the south; the Tiv in the southeast; the Idoma in southwest; and the Gade and Gbagyi in the west while the Hausa and Fulani live throughout the state. Nasarawa is also religiously diverse as about 61% of the state's population are Muslims with the remaining 39% being Christian and followers of traditional ethnic religions. In the pre-colonial period, the area that is now Nasarawa State was split up between various states with some states being tiny and village-based as others were part of larger empires until the early 1800s when the Fulani jihad annexed the region and placed the area under the Sokoto Caliphate as the vassal states of Keffi, Lafia, and Nassarawa. In the 1890s and 1900s, British expeditions occupied the area and incorporated it into the Northern Nigeria Protectorate.