"Arriére-Coin" is French for "Back corner" (and pronounced something like "ahrhear-kwa"). Blaise de Monluc evidently was the first to devise this handy and effective technique at the siege of Thionville in 1558 for dealing with counterattacking enemy who broke into the saps: "What I did was to make a little return every twenty paces, sometimes extending to the left and sometimes to the right. These extensions were wide enough to accommodate twelve or fifteen soldiers with their arquebuses and pikes. My object is building the returns was to permit the men to beat off any enemy who might capture the head of the sap and jump inside the trench." An arriére-coin permitted a handful of besiegers to crouch out of sight behind a turn in the zigzagging trench and then spring out behind any enemy who was so bold as to tred that way.