After the establishment of Scottish independence, Robert I turned his attention to building up a Scottish naval capacity. This was largely focused on the west coast, with the Exchequer Rolls of 1326 recording the feudal duties of his vassals in that region to aid him with their vessels and crews. Towards the end of his reign he supervised the building of at least one royal man-of-war near his palace at Cardross on the River Clyde. In the late fourteenth century naval warfare with England was conducted largely by hired Scots, Flemish and French merchantmen and privateers. James I took a greater interest in naval power. After his return to Scotland in 1424, he established a shipbuilding yard at Leith, a house for marine stores, and a workshop. King's ships were built and equipped there to be used for trade as well as war, one of which accompanied him on his expedition to the Islands in 1429. The office of Lord High Admiral was probably founded in this period. In his struggles with his nobles in 1488 James III received assistance from his two warships the "Flower" and the "King's Carvel" also known as the "Yellow Carvel".