Port Harcourt is the capital of Rivers State, Nigeria. It lies along the Bonny River and is located in the Niger Delta. According to the 2006 Nigerian census Port Harcourt has a population of 1,382,592. The Mayor of Port Harcourt City is Chimbiko Akorolo. From Iguocha Port Harcourt was renamed by Frederick Lugard after Lewis Vernon Harcourt in 1913 who was the Secretary of State for the Colonies.The area that became Port Harcourt in 1913 was originally the farmlands of the Diobu village group of the Ikwerre, an Igbo sub-group. The colonial administration of Nigeria created the port to export coal from the collieries of Enugu located 151 miles north of Port Harcourt, which it was linked to by a railway called the Eastern Line, also built by the British.Commercial quantities of crude oil was discovered in Oloibiri in 1956 and Port Harcourt's economy turned to petroleum when the first shipment of Nigerian crude oil was exported through the city in 1958. Through the benefits of the Nigerian petroleum industry Port Harcourt was further developed with aspects of modernisation such as overpasses and city blocks. Oil firms that currently have offices in the city include Royal Dutch Shell and Chevron.Port Harcourt's primary airport is Port Harcourt International Airport located in the periphery of the city; the Nigerian Air Force base is the location of the only other airport in the city, used by commercial airlines Aero Contractors and Virgin Nigeria for domestic flights. The main educational establishment in the city is the University of Port Harcourt.