In November 1917 the ‘Comrades of the Great War’, a non-political organisation, was formed in response to the number of returnees who were injured or invalided out of the War.  On 21st February 1918 a public meeting was held in the Kings Head hotel in Horsham where Mr H Metcalfe of the General Committee, Headquarters, London would speak. On 13th April 1918 premises in Horsham, at the corner of Park Street and East Street, were opened as the 'Comrades of the Great War Club' and at the opening ceremony Horsham town was congratulated upon being the first to start a club in the County.

In 1921 the ‘Comrades’ organisation amalgamated with three others to form The British Legion, becoming the Royal British Legion in 1971.

The Horsham Branch was officially registered on 23rd September 1922.