Complex sentence: He saw action in the Crimean War as an officer in the British Army, for this service he was appointed a Chevalier of the Legion of Honour by the Government of France on 16 July 1856.
Split into simpler sentences: He saw action in the Crimean War as an officer in the British Army. For this service he was appointed a Chevalier of the Legion of Honour by the Government of France on 16 July 1856.