James was born in Holyrood Abbey. He was the son of King James I and Joan Beaufort. By his first birthday his twin and only brother, Alexander, who was also the older twin, had died, thus making James the heir apparent and given the title Duke of Rothesay. On 21 February 1437, James I was assassinated and the six-year-old James immediately succeeded him as James II.
James II enthusiastically promoted modern artillery, which he used with some success against the Black Douglases. His ambitions to increase Scotland's standing saw him besiege Roxburgh Castle in 1460, one of the last Scottish castles still held by the English after the Wars of Independence. For this siege, James took a large number of cannons imported from Flanders. He was standing near one of these cannons, known as "the Lion", when it exploded and killed him. (Wikipedia).
N. Mayhew, ‘The contemporary valuation of the fleur-de-lis groats of James I and II’, 58 (1988), 130-32
M. L. Stavert, ‘James II and his mints: an unknown document’, 58 (1988), 132-34