Hillingdon is an area of Uxbridge within the London Borough of Hillingdon, centred 14.2 miles west of Charing Cross. It was an ancient parish in Middlesex that included the market town of Uxbridge. During the 1920s the civil parish bore a rapid, planned increase in population and housing, and was absorbed by Uxbridge Urban District in 1929. It has formed part …Hillingdon is an area of Uxbridge within the London Borough of Hillingdon, centred 14.2 miles west of Charing Cross. It was an ancient parish in Middlesex that included the market town of Uxbridge. During the 1920s the civil parish bore a rapid, planned increase in population and housing, and was absorbed by Uxbridge Urban District in 1929. It has formed part of Greater London since 1965.