Query: The French Marines and naval infantry were dispatched to reinforce what?
Context: The French Marines and naval infantry intended for the invasion of northern Germany were dispatched to reinforce the French Army of Châlons and fell into captivity at Sedan along with Napoleon III. A shortage of officers, following the capture of most of the professional French army at the Siege of Metz and at the Battle of Sedan, led naval officers to be sent from their ships to command hastily assembled reservists of the Garde Mobile.