Maransin participated in
Andoche Junot's invasion of Portugal and was stationed in the southern province of
Algarve when the revolt against French occupation broke out. When his bedridden commanding officer
Antoine Maurin was captured by the Portuguese, Maransin gathered up the troops in the province. These 1,200 men included the Legion du Midi and a battalion of the 26th Line Infantry Regiment. He successfully withdrew to
Lisbon via
Mértola and
Beja. He fought at the
Battle of Albuera on 16 May 1811. Maransin's final promotion to the rank of
Général de Division occurred on 20 May 1813, and he was named Commander of the
Légion d’Honneur on 15 December 1814. ==Notes==