Gruffudd ap Llywelyn ap Iorwerth
Gruffudd ap Llywelyn ap Iorwerth (c. 1200 – 1 March 1244) was the son of Llywelyn the Great, he was illegitimate, however in Welsh law he was allowed to become Prince, however Llywelyn wanted Dafydd ap Llywelyn to become the next prince, he died in 1244 whilst attempting to escape the Tower of London, after being imprisoned by King John as a hostage.