With Debussy’s adoption of a markedly nationalist position at the onset of World War I, in appending the epithet ‘musicien français’ to his name, it was by no means evident during the years immediately following his death that he would, in time, become one of the most influential figures for later twentieth- and early twenty-first-century composers in France and elsewhere. While his music endured in the interwar years, his musical and aesthetic concerns were largely rejected or eclipsed. In 1956 Boulez identified Debussy as forming part of a peculiarly French axis of aesthetic modernists – Debussy-Cézanne-Mallarmé, ‘a solitary church spire’ and ‘an excellent ancestor’. This chapter investigates ways in which Debussy’s music and ideas implicated themselves within the work of composers active after 1945 from Messiaen, Jolivet, Dutilleux and Ohana through the work of Boulez and Barraqué to his continued influence on various branches of contemporary French composition, not least the Spectralists.