Origins of the Clan
The origins of the name "Borthwick" are territorial. The name seems likely to have been assumed from Borthwick Water in Roxburghshire.

It is traditionally held that the first of the noble house was Andreas, who accompanied the Saxon Edgar Ætheling and his sister, Saint Margaret of Scotland, to Scotland in 1067. The family soon rose to prominence.

Clan Borthwick is a Scottish clan and one of the most ancient families in Scotland. It has recently been suggested that the family may have come to Britain with the Romans and Julius Caesar's legions.

Edgar Ætheling[1], also known as Edgar the Outlaw, (c. 1051 – c. 1126?) was the last male member of the West Saxon royal house of Cerdic. He was proclaimed, but never crowned, King of England.

Born in Hungary, Edgar was the only son of Edward the Exile, heir to the English throne, and was a grandson of King Edmund II ("Edmund Ironside"). Upon his father's death in 1057, Edgar was nominated as heir apparent by his great-uncle King Edward the Confessor. However, he was too young at the time of the King's death in January 1066 to defend the country against the impending Norman invasion led by William of Normandy, so a Witenagemot instead elected Harold Godwinson, King Edward's brother-in-law, as King Harold II. Following the death of Harold II at the Battle of Hastings on Saturday, 14 October 1066, Edgar was proclaimed King Edgar II by a Witenagemot in London. He was never crowned and submitted to William I some six to eight weeks later, at the age of about fourteen or fifteen.