The clan is named after the river and lands of Blackadder in Berwickshire. Adam of Blackathir was one of those sent to conduct the envoys with Princess Cecilia’s dower to Edinburgh in 1477, and in 1486 Charles Blackater had protection and safe conduct to travel in England.
Robert Blackadder was bishop of Glasgow at the end of the 15th century. Rolland Blaykatter, tenant in the barony of Glasgow in 1521 may be the same Roland Blacadyr who appears as sub-dean of Glasgow in 1524. Thomas Blacater was Bailie of the Commendator of Coldingham in 1557.
The name was common in Lanarkshire in the 16th century and the Blacaters of Tulliallan in Perthshire (from which they were disposessed in 1632) were an offshoot of the Border family.
John Blackadder of Tulliallan was an eminent minister of the Church of Scotland. He was imprisoned on the Bass Rock as a Covanenter and died there in 1685.
Old Tulliallan Castle, Fife. The castle came into possession of the Blackadder family through marriage sometime in the latter half of the 15th century. The Blackadders remained at Tulliallan until 1662.