The H1 started in September 2001 to act as the only bus service linking Loughton and Debden to Harlow replacing the Harlow to Debden section on route 502 which previously operated from Harlow to Romford. The route originally served Princess Alexandra Hospital and Harlow Town Station in Harlow, but the route was soon shortened just to serve the bus station. In May 2007, the extension was re-instated and terminated at Edinburgh Way Tesco. On 17 November 2007, the route was extended from Edinburgh Way to Old Harlow Post Office, and a loop was introduced around Loughton and Debden so that it served Epping Forest College, Borders Lane and Newmans Lane. On 22 March 2008, the extension between Edinburgh Way and Old Harlow was discontinued and a revised routing around Loughton and Debden was intro