Marmaduke Thweng, 1st Baron Thweng Castle by the English leader John de Warenne, 6th Earl of Surrey. The castle was quickly starved into submission, and Thweng and FitzWarin were taken prisoner to Dumbarton Castle. He was summoned to Parliament in 1307, thus becoming Baron Thweng. At the Battle of Bannockburn in 1314, however, after the English defeat, Sir Marmaduke apparently made no attempt to escape. Instead he wandered over the battlefield until he located Robert the Bruce; only then was he prepared to surrender, and only to the victorious King. Robert recognised Sir Marmaduke and released him and Ralph de Monthermer, also captured, both without
Robert the Bruce planned a major military campaign with the support of Lancaster and the barons, mustering a large army of between 15,000 and 20,000 men. In the spring of 1314, Edward Bruce laid siege to Stirling Castle, a key fortification in Scotland whose governor, Philip de Mowbray, agreed to capitulate if not relieved before 24 June 1314. In March, James Douglas captured Roxburgh, and Randolph captured Edinburgh Castle, while in May, Bruce again raided England and subdued the Isle of Man. News of the agreement regarding Stirling Castle reached the English king in late May, and he decided to speed his march