Plympton Castle was the chief residence of the Earls of Devon and Lords of Plympton. King Henry, the youngest son of the Conqueror, in the first year of his reign, granted the Lordship to Richard de Redvers or Rivers and his posterity, to enjoy also the title and possessions belonging to the Devonshire Earldom. The said Richard was one of William the Conqueror’s generals in the battle of Hastings, and obtained the barony of Okehampton from William Rufus. He was one of the chief councillors of Henry the First, and was so highly esteemed by him that he was created first Earl of Devon since the Conquest. The castle stood on the north side of the town, occupying a space of about two acres, extending 700 feet from east to west, including the ditch, and 400 feet from north to south. Leland says of this structure, in his Itinerary, “On the side of the town is a fair large castelle and dungeon in it, whereof the walls yet stand, though the lodgings be clean decayed.” At present there only remains a portion of the circular keep or tower, fifty feet in diameter, on a mound about sixty feet high. The ruined walls average fourteen feet in height and are nine feet thick, grouted with mortar or concrete as hard as the stones themselves. Around the keep in the thickness of the wall is a plastered flue, fifteen inches by ten inches, the purpose of which is not obvious. It has been suggested that it was designed for the conveyance of sound. It seems more probable that it was for ventilation. There is a similar flue at Rochester Castle. The habitable portions of Plympton Castle must have been of considerable extent. These, including the state apartments, and lodgings (as Leland calls them) for the military and retainers, were within the outer castle walls, and built around a spacious basse-court. The ballium wall—embattled and flanked with towers—was raised on a platform about 30 feet above the fosse or ditch, in the position now indicated by a modern path, and by a belt of trees planted about a hundred years ago. The basse-court has long been a quiet village green, and the site of the ballium wall, where stern warriors peered over frowning battlements, is now a “lovers’ walk.” Such are the tendencies of modern civilization. Surrounding the castle wall was a deep moat about 40 feet wide, still to be traced, except on the eastern side, where it has been filled up. In Leland’s time it was full of water, and stored with carp. There are no remains whatever of the great gateway of the castle (with its drawbridge and portcullis), which, as shewn by the seal of the Lords of Plympton, was on the north side. There were probably towers at the different angles.