Complex sentence: When the Second World War broke out, Lesage was called up in August 1939, demobilized on 12 July 1940 and decided to go to Vichy to see if he could be of service to the community under the new French government.
Split into simpler sentences: When the Second World War broke out, Lesage was called up in August 1939. After he was demobilized on 12 July 1940 he decided to make his way to Vichy to see if he could be of service to the community under the new French government.