Complex sentence: The Maréchal de Schomberg, having crossed the village of La Couarde, is informed by Marillac of the British position: the British vangarde is starting to engage itself, slowly, because of the narrowness, on the bridge of Feneau.
Split into simpler sentences: The Maréchal de Schomberg, having crossed the village of La Couarde, was informed by Marillac of the British position. The British vanguard started to engage itself, slowly, because of the narrowness, on the bridge of Feneau.