Chenu was born on 7 January 1895 at Soisy-sur-Seine, Essonne, and grew up under the name Marcel-Leon.
Chenu entered the French Province of the Dominican Order in 1913, taking the name Marie-Dominique and studying at Le Saulchoir, which at the time was located (as a result of the French anti-Church laws of 1905-6) at Kain in Belgium [REF].