Andrew Harclay, 1st Earl of Carlisle the Scots, under the command of Robert the Bruce, at the Battle of Old Byland in Yorkshire. The English commander, John of Brittany, Earl of Richmond, was taken prisoner, while the king himself barely escaped capture. It was the worst defeat the English had suffered in the wars since the Battle of Bannockburn in 1314. Harclay had received a summons to join the royal army, but had not been able to bring his troops south in time to come to the king's rescue. The event convinced him that the war against Scotland could not be won under the leadership of
Robert the Bruce to his eldest son, Robert, the future king, so as to protect the Bruce's kingship claim while their middle lord (Robert the Bruce's father) now held only English lands. While the Bruces' bid for the throne had ended in failure, the Balliols' triumph propelled the eighteen-year-old Robert the Bruce onto the political stage in his own right. Even after John's accession, Edward still continued to assert his authority over Scotland and relations between the two kings soon began to deteriorate. The Bruces sided with King Edward against King John and his Comyn allies. Robert the Bruce and his father both