One of the great medieval offices of state, derived from comes stabuli, count of the stables. The first lord high constable was a supporter of the Empress Matilda, who made him earl of Hereford. It then passed to the Bohuns, on to Thomas of Woodstock, and to his descendant Edward, duke of Buckingham, executed by Henry VIII in 1521. It had acquired responsibility for the mobilization of the army, for the enforcement of martial law, and for adjudication on matters of chivalry. Scottish constables commanded the army and from the time of Robert I the office became hereditary in the Hay family, earls of Erroll.