Complex sentence: In may 1940, though he is exempt from duty, Tanguy-Prigent asks to join the front with the 31st regiment (Dragons Portés) and is lightly wounded at the "Bataille de France".
Split into simpler sentences: In may 1940, though exempt from duty, he asked to join the front with the 31st regiment (Dragons Portés). He was lightly wounded at the "Bataille de France".