The political party was established during the Sivas Congress in 1919 as a union of resistance groups against the Greek invasion of Anatolia. The union represented Turkish people as a unified front during the Turkish War of Independence (1919–1923). On 9 September 1923, the "People's Party" declared itself to be a political organization and on 29 October 1923, announced the establishment of the Turkish Republic. On 10 November 1924, the People's Party renamed itself the "Republican People's Party" (CHP) as Turkey moved into a one-party period.