Complex sentence: He remained loyal to the House of Bourbon, becoming a military commander under Louis Antoine, Duke of Angouleme and later serving briefly as French ambassador to the Court of St James's under the Bourbon Restoration.
Split into simpler sentences: He remained loyal to the House of Bourbon, becoming a military commander under Louis Antoine, Duke of Angouleme. He later served briefly as French ambassador to the Court of St James's under the Bourbon Restoration.