April 11th , 1240
Llywelyn ab Iorwerth (c. 1173–April 11, 1240) was a Prince of Gwynedd: and eventually ruler over much of Wales. Llywelyn was a decendant of the senior line of Rhodri Mawr, thus a member of the princely house of Aberffraw. Although he is often referred to as a Prince of Wales, his official title was Prince of Aberffraw and Lord of Snowdonia (the first official Prince of Wales was his son, Dafydd). He was also known as Llywelyn the Great or, in Welsh, Llywelyn Fawr, one of only two Welsh rulers to bear this title, the other being Rhodri the Great.
Llywelyn appears to have suffered a paralytic stroke in 1237, and from this time on his heir Dafydd: took an increasing part in the rule of the principality. Dafydd: imprisoned his brother Gruffydd, and held him in Criccieth Castle. Llywelyn died in 1240 at the Cistercian abbey of Aberconwy which he had founded, and was buried there. This abbey was later moved to Maenan near Llanrwst, and Llywelyns stone coffin can now be seen in Llanrwst parish church.