Ever since his defeat at Bannockburn in 1314, Edward II had been preoccupied by an ongoing political struggle with his senior barons, headed by Thomas, Earl of Lancaster. Repeated Scottish raids deep into the north of England had effectively been ignored: but the loss of Berwick was something different. Once the most important port in Scotland, it had been in English hands since 1296; during which time its defences had been greatly strengthened.
Since his defeat at Bannockburn in 1314, Edward II had been consumed by a persistent conflict with his powerful nobles, spearheaded by Thomas, Earl of Lancaster. The Scottish raids into northern England had been largely ignored: but the loss of Berwick was a different matter altogether. As Scotland's most vital port since 1296, its capture marked a significant shift in power.