SERGEANT-AT-ARMS, or Mace, an officer appointed to attend the person of the king, to arrest traitors, and such persons of quality as offend, and to attend the lord high-steward when sitting in judgment on a traitor. There are four other sergeants-at-arms, created in the same manner; one, who attends the lord-chancellor; a second, the lord-treasurer; a third, the speaker of the House of Commons; and a fourth, the lord mayor of London on solemn occasions.