A feature of British maritime history predominant up until the Barons' Wars was found in the appointment of one or more persons, 'sometimes for one county and sometimes for a group of counties, as keepers of the coast', which led in time to the consolidstion of the powers of the Lord Warden of the Cinque Ports.

John Marshal was keeper of the ports of Somerset and Dorset in 1215, and in 1224 Ralph Germun was a keeper of the Dorset coast. In the year 1230 Geoffery de Lucy was Warden of Portsmouth, Hythe and Romney, Constable of Dover Castle. Henry de Sandwich was warden of Dover and Sandwich, whilst Shoreham, Winchelsea, Rye, Hastings, Seaford and Pevensea were under the administration of the Constable of Hastings.

In 1235 Hamo de Crevecur, who was appointed Lord Warden in 1263 shared joint control with Walerand Teutonicus, of the coast between Hastings and Poole, in Dorset.

The office was not continuous, and such men were more often called upon during a time of war, or when a threat was perieved in the Channel. Thus such records have survived for the reign of Edward III preceeding the battle of Sluys in 1340.

In addition to a military command both at sea and on land, judicial matters relating to the sea and coast came within the Keepers remit.

"Practically, he was expected to crush piracy, to beat off raiders, to enable coasters and fishermen to sail in peace, and to summon the county to arms upon invasion. A part of the system of defence under the care of the keeper was the line of fire beacons, corresponding to the modern coastguard stations, usually placed on a hill near the shore and guarded in war time by a watch from the neighbouring parishes."