Clovis, King of the Franks, was baptised in 496. France as such did not exist then, but it did earn the title of “eldest daughter of the Church”. The relationship of France and the Church has been similar to that of a rebellious child with its parent: moments of harmony but also clashes and revolts. The Wars of Religion and the French Revolution were painful episodes that left deep scars. The culmination was the separation of the Church and the State in 1905.
France is now a secular state.