[1] It has also been suggested that he was a nephew of Piers Gaveston, Edward II of England's favourite.
In 1315 the harvest failed in southern Scotland and Northern England and by winter the garrison at Berwick was at such extremity that they were forced to eat their horses, and was being affected by desertion.
[7] Caillou and others of the Gascons suggested a raid into Scots held territory to replenish the stores of the Castle, Berkeley refused his permission as the countryside was full of Scots soldiery, and his main commission was the defence of the town and castle of Berwick.
[9] Caillou's company once they had seized sufficient spoils returned towards Berwick driving the cattle before them.
Caillou ordered the cattle and prisoners on to Berwick, and formed up in battle line to meet Douglas.