He invented a type of aircraft propeller used by the French army during World War I and founded the Bloch aircraft company. Following the nationalization of his company in 1936, under the Front Populaire, he stayed as an employee.
As a Jew, he was deported to Buchenwald during World War II.
He changed his name from Bloch to Dassault in 1945, hiding his Jewish origins. Dassault was the pseudonym of his brother, General Paul Bloch, in the French resistance and means "for assault", as in assault weapon.
After the war, Dassault built the foremost military aircraft manufacturer in France, Avions Marcel Dassault. He was succeeded by his son Serge as head of the group.