Durham County Council is the local authority of County Durham (excluding Darlington, Hartlepool and Stockton-on-Tees) in North East England. Since 2009 it has been a unitary authority, having the powers of a non-metropolitan county and district council combined. From 1889 to 2009 it was a county council in a two-tier arrangement.At the time of the 2011 census it served a population of 513,200, which makes it one of the most-populous local authorities in England.