The International Workingmen's Association (IWA), commonly known as the First International, was a political international which aimed to unite a variety of left-wing political groups and trade union organizations based on the working class and class struggle. It was founded on 28 September 1864 at a workers' meeting in St Martin's Hall, London, and its first congress was held in 1866 in Geneva.
The IWA's history was characterized by internal conflicts between different socialist and anarchist factions. The initial ideological struggle was between the communists or Marxists, centred around Karl Marx on the General Council, and the mutualists or followers of Pierre-Joseph Proudhon. The communists successfully displaced the mutualists as the dominant ideological trend at the Brussels Congress in 1868. The rise of Mikhail Bakunin's collectivist anarchist faction in the late 1860s led to a more intense conflict over the role of the state and political action in achieving socialism. The organization reached its peak following the Paris Commune of 1871, which was celebrated and defended by the International in Marx's influential address, The Civil War in France. The bloody suppression of the Commune, however, led to a period of harsh government repression against the IWA.