Military history of Scotland for Robert I's success was his ability to call on naval forces from the Islands. As a result of the expulsion of the Flemings from England in 1303, he gained the support of a major naval power in the North Sea. The development of naval power allowed Robert to successfully defeat English attempts to capture him in the Highlands and Islands and to blockade major English controlled fortresses at Perth and Stirling, the last forcing Edward II to attempt the relief that resulted at English defeat at Bannockburn in 1314. Scottish naval forces allowed invasions of the Isle of Man
Robert the Bruce queen dowager) are unlikely but not impossible. Bruce and his followers returned to the Scottish mainland in February in two groups. One, led by Bruce and his brother Edward, landed at Turnberry Castle and began a guerrilla war in south-west Scotland. The other, led by his brothers Thomas and Alexander, landed slightly further south in Loch Ryan, but they were soon captured and executed. In April, Bruce won a small victory over the English at the Battle of Glen Trool, before defeating Aymer de Valence, 2nd Earl of Pembroke, at the Battle of Loudoun Hill. At the same time, James