born in brest, finistère, cornut-gentille studied at the école libre des sciences politiques. in 1943 he was appointed as the subprefect of reims, but resigned to assist the free french delegate émile bollaert. following the liberation of france he served as prefect of ille-et-vilaine, of the somme, and of the bas-rhin. in 1948 he was appointed high commissioner in french equatorial africa then, from 1951 to 1956, high commissioner in french west africa.