Complex sentence: The fourth son of Claude Gérard of Masmünster in Alsace by his wife Marie-Françoise Wetzel, his eldest brother was Conrad-Alexandre Gérard, comte de Munster.
Split into simpler sentences: The fourth son of Claude Gérard, of Masmünster in Alsace, by his wife Marie-Françoise Wetzel. His eldest brother was Conrad-Alexandre Gérard, comte de Munster.