Royal Navy 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 King 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 in 1313 and 1317 and Ireland in 1315. They were also crucial in the blockade of Berwick, which led to its fall in 1318. With the Viking era at an end, and
Battle of Allt Camhna they were guilty of treachery, which is much worse than a defeat. The day and place were fixed for their meeting the Caithness men, and they did not appear, but allowed those to be cut down by a host which had laid their accounts to have the combined forces of Caithness and Sutherland to contend with"". 17th-century historian Sir Robert Gordon (1580–1656), who was living at the time of the battle and who was a younger son of Alexander Gordon, 12th Earl of Sutherland, wrote an account of the battle in his book "A Genealogical History of the Earldom of