In 1883, H. M. Hyndman eastablished the Social Democratic Federation (SDF). It became the first Marxist political group in Britain and over the next few months Hyndman was able to recruit members such as Tom Mann, John Burns, Eleanor Marx, William Morris, George Lansbury, Edward Aveling, H. H. Champion and Ben Tillet.
Some members of the SDF disapproved of Hyndman's doctorial style and the way he encouraged people to use violence on demonstrations. In December 1884 William Morris and Eleanor Marx left to form a new group called the Socialist League. H. H. Champion, Tom Mann and John Burns also left the party. Although the membership was never very large, the SDF continued and in February 1900 the group joined with the Independent Labour Party, the Fabian Society and several trade union leaders to form the Labour Representation Committee (LRC). The LRC eventually evolved into the Labour Party. Many members of the party were uncomfortable with the Marxism of the SDF and Hyndman had very little influence over the development of this political group. In August 1901 the SDF disaffiliated from the Labour Party.
In 1902 several political activists left the Social Democratic Federation (SDF), an organization led by H.L. Hyndman, to form the Glasgow Socialist Society. Eventually, most of the members of the SDF in Scotland joined this new group. In August 1903 it was renamed the Socialist Labour Party (SLP). The following year the SDF was renamed as the British Socialist Party (BSP).
The outbreak of the First World War caused a split in the BSP. Some members such as Albert Inkpin and John Maclean were opposed to British involvement in the war and supported the programme of the Zimmerwald Conference. As James Klugman has pointed out in his book, The History of the Communist Party of Great Britain (1969): "Divided on its attitude to the war, the consistent internationalists, opposing the war as imperialist and reactionary, had defeated Hyndman and the majority of the old pro-war Executive at the 1916 Conference." As a result of this vote, H.L. Hyndman and his supporters left the BSP to form the National Socialist Party.
Mark Hayes argues in The British Communist Left (2005) argues that: "The final departure of the social pacifist leadership of the British Socialist Party in late 1919 left a sizeable social democratic minority still intact within the party, with a political base among those holding positions as officials in local government and the trade unions."
John Maclean, Albert Inkpin, Harry Pollitt, Willie Gallacher and John R. Campbell became the new leaders of the British Socialist Party. In 1913 Inkpin was elected as the General Secretary of the BSP. He also edited the party newspaper, The Call (1916-1919). As James Klugman has pointed out: "Of the 6,000 or so claimed in 1920, many were members on paper only. It was more a propagandist than an agitating, campaigning body, and often rather isolated from the mass of the workers."
In April 1920 members the British Socialist Party merged with other left-wing groups formed the Communist Party of Great Britain (CPGB). The new party included Tom Bell, Willie Gallacher, Arthur McManus, Arthur Horner, Harry Pollitt, John R. Campbell, Helen Crawfurd, Albert Inkpin, A. J. Cook, Bob Stewart, Rajani Palme Dutt and Willie Paul to establish the Communist Party of Great Britain (CPGB). McManus was elected as the party's first chairman and Bell and Pollitt became the party's first full-time workers.