There aren’t that many Plymouth place-names that owe their origin directly to the outcome of that famous battle in Hastings in 1066, but Earl’s Acre is one of them. After his success in Sussex almost a thousand years ago, William the Conqueror returned to Normandy in the early summer of 1067, however, trouble in the westcountry where the defeated and dead King Harold’s mother still had land and influence, brought him swiftly back.
After besieging and capturing Exeter, King William ordered the construction of Rougemont Castle and subsequently commissioned castles to be built at Totnes, Trematon, Restormel, Launceston and Plympton. The latter he conferred upon his second cousin, Baldwin Redvers, and while the Breton, Judhel, held most of the land in Plymouth, Earl Baldwin’s family, in addition to the whole manor of Plympton, also ‘later acquired a small parcel still remembered in the name of a row of houses in Alma Road, Earl’s Acre’ (Crispin Gill – Plymouth A New History). It is also, incidentally, why Plympton St Maurice was long known as Plympton Erle.