Tewdwr Mawr (the Great) ap Cadell  24
- Marriage: Gwenllian 
Tewdwr Mawr, King of South Wales is the son of Cadell (?).
Tewdwr Mawr, King of South Wales gained the title of King Tewdwr Mawr of South Wales.1 Tewdwr Mawr, King of South Wales also went by the nick-name of Tewdwr Mawr (?) (or in English, 'the Great').1 He was also known as Gruffydd (?).
Charles Mosley, editor, Burke's Peerage, Baronetage & Knightage, 107th edition, 3 volumes (Wilmington, Delaware, U.S.A.: Burke's Peerage (Genealogical Books) Ltd, 2003), volume 2, page 2297. Hereinafter cited as Burke's Peerage and Baronetage, 107th edition.
Tewdwr married Gwenllian  [MRIN: 2035], daughter of Gwyn ap Rhytherch Lord of Dyvet  and Unknown.