Arthur, Duke of Rothesay

Arthur Stewart, Duke of Rothesay (20 October 1509, Holyrood Palace - 14 July 1510, Edinburgh Castle) was the second son of James IV of Scotland and Margaret Tudor, and had he outlived his father, James IV of Scotland would have been King of Scotland, he was named after his uncle Arthur, Prince of Wales, who like his namesake had he outlived his father, would have been King of England. He is the 14x Great uncle of the current Queen, Elizabeth II of the United Kingdom.

At the time of his birth, James IV had survived his own brothers. His only previous legitimate son James, Duke of Rothesay had died the previous year. The newborn Duke of Rothesay and his father were the only living descendants of his paternal grandfather James III of Scotland. The Heir presumptive since 1508 was John Stewart, Duke of Albany, a nephew of James III.

The young Duke died only a year after his birth. His death left James IV again childless and the Duke of Albany again heir to the throne. His younger brother would not be born until 1512 but would eventually succeed as James V of Scotland.

http://en.wikipedia.org/wiki/Arthur_Stewart,_Duke_of_Rothesay

http://thepeerage.com/p10500.htm#i104993