In 1330, Sir Alexander de Cokburne became the Baron of Langton (in Berwickshire), Carriden (in West Lothian) and Bolton (in East Lothian) following his marriage to the wealthy Anglo-Norman heiress Mariota de Veteriponte (also known as Maria de Vipont). The Langton estate was located to the southwest of Duns, about 6 km from Cockburn Tower. Sir Alexander's second marriage to the heiress Maria de Monfode added the estate of Skirling (in Peeblesshire). The greatly enlarged Cockburn lands were split up among Sir Alexander's three sons; however, the barony of Langton and Carriden remained with the eldest son Alexander. For the next 400 years, the Cockburns of Langton were prominent landowners in Berwickshire. Other branches of the family acquired estates in Ormiston and Clerkington (just southwest of Haddington) in East Lothian. The Cockburns of Henderland held land in Megget then in southern Peeblesshire, while the Cockburns of Skirling held land in the western part of Peebleshire.