The Ernest Cognacq Museum (French: Musée Ernest Cognacq) is a French regional history museum, located in the city of Saint Martin de Ré, Île de Ré, France. The museum is housed in the "Hotel de Clerjotte", built in 1470-1480 by Louis Clergeat, taxman for Charles de France, Duke of Guyenne, and master of Île de Ré. Clergeat seems to have given his name to the building (the "House of Clergeatte") to become "Hotel de Clerjotte" today. The building was expanded in the 16th and 17th centuries, with two lateral constructions equipped with hallways and arcades. In 1684, Jean Gabaret, Lieutenant General of the Royal Navy and a Protestant, became the owner of the house. With the rise of nearby Rochefort as a key shipbuilding harbour for the Royal French Navy, Saint Martin de Ré was fortified follow