The London Borough of Barnet is a suburban London borough in North London. The borough was formed in 1965 from parts of the ceremonial counties of Middlesex and Hertfordshire. It forms part of Outer London and is the largest London borough by population with 384,774 inhabitants, also making it the 13th largest district in England. The borough covers an area of 86.74 square kilometres (33 sq mi), the fourth highest of the 32 London boroughs, and has a population density of 45.8 people per hectare, which ranks it 25th. The local authority is Barnet London Borough Council, based in Colindale.