Kingdom of Scotland 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 in English defeat at Bannockburn in 1314. Scottish naval forces allowed invasions of the Isle of Man in 1313 and 1317 and Ireland in 1315. They were also crucial in the blockade of Berwick, which led to its fall in 1318. After the establishment of Scottish independence, Robert
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