Thomas Randolph was the son of one of Robert the Bruce's sisters. Randolph first appeared on the Scottish scene when he joined his uncle's fight for the Scottish throne in 1306. Unfortunately, he was almost immediately captured at the Battle of Methven. The battle was a disaster for Bruce and rather than allowing the captured to be ransomed (as was normally the case in medieval warfare), Edward I had the captives hanged, drawn and quartered or beheaded without trial. Thomas Randolph was saved because of his friendship with the Earl of Pembroke. He was granted a pardon on condition he fight for the English.
True to his word, Randolph fought for the English until he was captured by Douglas near Peebles during the summer of 1308. When Douglas took Randolph to his uncle, who reproached him for fighting for the English, Randolph reportedly retorted that the Bruce, "made war like a brigand instead of fighting a pitched battle as a gentleman should."(1) Despite the criticism the Bruce put Randolph under Douglas' close supervision.
Randolph became one of Bruce's greatest captains. Perhaps his best known martial accomplishment is the capture of Edinburgh Castle in March 1314. With a small band of men Randolph scaled the north face of the rock while the main body of his troop attacked the south gate. Randolph and his men were able to enter the castle and open the gate to his main force, which then took the castle. Around this time (1312 or 1314), Robert I made Randolph Earl of Moray.
Randolph further distinguished himself at Bannockburn. With Douglas he took Berwick-on-Tweed in 1318 and defeated the English at Byland, Yorkshire (1322).
He was a skilled diplomat as well as warrior. His efforts helped persuade Pope John XXII to recognize Robert's right to the Scottish throne (1323). In 1326 Randolph headed the delegation which negotiated the Treaty of Corbeil, forming a defensive alliance with France. In 1328 he helped negotiate the treaty by which the English recognized Robert King of Scots.
When Robert I died in 1329 Randolph was made regent for David II. The last survivor of Bruce's great captains, he died three years into the regency.
Information from:
(1)
Robert the Bruce : King of Scots
Ronald McNair Scott, Peter Bedrick Books
New York, 1982
and
"Moray, Thomas Randolph, 1st Earl of" Britannica Online.