The Sultan's Household troops formed a class apart; for though connected with the standing army, they were looked on more as a department of the Court than a division of the army.[…]The Imperial Chawushes (sergeants) were a similar body, four or five hundred strong. In time of war they acted as guides to the army, marechaux-de-camp, provosts and gallopers; in time of peace as messengers and ushers of the Court.
Source: wiktionary