Complex sentence: He was married to Geneviève Lamirand, the daughter of Georges Lamirand (1899--1994), the latter had been Vichy France General Secretary of Youth from September 1940 to March 1943 but the family was Free French.
Split into simpler sentences: He was married to Geneviève Lamirand, the daughter of Georges Lamirand (1899--1994). The latter had been Vichy France General Secretary of Youth from September 1940 to March 1943 but the rest of the family was Free French.