The Lord High Constable of England is the seventh of the Great Officers of State, ranking beneath the Lord Great Chamberlain and above the Earl Marshal. His office is now called out of abeyance only for Coronations. The Lord High Constable was originally the commander of the royal armies and the Master of the Horse. He was also, in conjunction with the Earl Marshal, president of the Court of Chivalry or Court of Honour. In feudal times, martial law was administered in the court of the Lord High Constable.

Holders of the office during the period covered:

At this point, the office merged with the Crown and was revived only for the Coronation of the British monarch.

More details and a fuller list of office holders on the Wikipedia page [1].