We should also put foward for consideration Edward II, who was born in Caernarfon.
He was also the first Prince of Wales, in it's modern sense. According to the legend, his father Edward I quelled a Welsh rebellion by promising the Welsh barons that he would appoint a new Prince of Wales as their overlord, 'a prince born in Wales, who did not speak a word of English'.
The Welsh were a bit miffed when they realised he was talking about his own infant son....
It's probably not true, as Edward of Caernarfon was 17 when he was made PoW, but sounds like a nice story IMO.