In 1296, Edward I, King of England, took him prisoner to England but, on 30 July 1297, he was released on condition of serving that king in his foreigh wars. From Robert I, King of Scots, in consideration of his faithful service, he received several grants and exchanged with the king Cardross, county Dunbarton, for the lands of Old Montrose, county Forfar. In 1320, Sir David signed the famous letter to the Pope, asserting the independence of Scotland. In 1322, he was one of the guarantees of a treaty with England. 

Source: Leo van de Pas