Individual Details

From Castles of Wales
http://www.castlewales.com/clare.html

Gilbert de Clare
The end of the Baronial revolt of the 1260s left Llywelyn ap Gruffydd as the only potential enemy of King Henry III. Prudently, Llywelyn decided to make peace, and by the Treaty of Montgomery (1267) he was recognized as "prince of Wales," and as the feudal lord of the other Welsh princes.
*******************

From thePeerage.com

Llywelyn ap Gruffydd, Prince of North Wales1
M, #102603, b. circa 1223, d. 11 December 1282
Last Edited=25 Oct 2009
Llywelyn ap Gruffydd, Prince of North Wales was born circa 1223.2 He was the son of Gruffydd ap Llywelyn and Senena ferch Rhodri.2 He married Lady Eleanor de Montfort, daughter of Simon de Montfort, 6th Earl of Leicester and Eleanor of England, in 1278. He died on 11 December 1282.2
He succeeded to the title of Prince of Wales in 1246.2
Child of Llywelyn ap Gruffydd, Prince of North Wales and Lady Eleanor de Montfort

Gwenllian ap Llywelyn b. 1282, d. 1337

Citations

[S11] Alison Weir, Britain's Royal Families: The Complete Genealogy (London, U.K.: The Bodley Head, 1999), page 71. Hereinafter cited as Britain's Royal Families.
[S130] Wikipedia, online http;//www.wikipedia.org. Hereinafter cited as Wikipedia.

Birth	Ca 1223
Death	11 Dec 1282
Alt name		Leweline
Title (Nobility)		Prince of Wales

Spouse

Joan ( - )