Operation Dingson (5–18 June 1944) was an operation in the Second World War, conducted by 178 Free French paratroops of the 4th Special Air Service (SAS), commanded by Colonel Pierre-Louis Bourgoin, who jumped into German occupied France near Vannes, Morbihan, Southern Brittany, in Plumelec, on the night of 5 June 1944 (11 h 30) with Captain Pierre Marienne and 17 men, then advanced to Saint-Marcel (8–18 June). At this time, there were approximately 100,000 German troops, and artillery, preparing to move to the Normandy landing areas.