The Welsh Genealogies as well as the Historia Brittonum tell us that Cunedda was the founder and first ruler of the kingdom of Gwynedd, followed by Einion Yrth and Cadwallon Lawhir. Which may or may not be true.
In any event, the exact dates placed on the rule of these three possible kings depends entirely on when it is assumed that Cunedda first came to north Wales, a date which varies from circa 385 AD to as late as 450 AD.
Hence the list starts with Maelgwyn, who is the first historically verifiable king of Gwynedd. It ends with Dafydd ap Gruffudd, the last native Welshman to have any claim to rule Gwynedd, although his predecessor and elder brother Llywelyn ap Grufudd was the last ruler that held significant power in Wales and is accordingly known as Llywelyn the Last.
The House of Maelgwyn
Maelgwyn Hir (517-547)
Rhun Hir (547-589)
Beli ap Rhun (c589-c599)
Iago ap Beli (c599-c615)
Cadfan ap Iago (c615-625)
Cadwallon ap Cadfan (625-634)
Usurper
Cadfael ap Cynfeddw (634-c655)
The House of Maelgwyn (restored)
Cadwaladr Fendigaid (c655-682)
Idwal Iwrch (682-712)
Rhodri Molwynog (712-754)
Caradog ap Meirchion (754-798)
Cynan Tindaethwy (798-816)
Hywel (814-825)
The House of Merfyn Frych
Merfyn Frych (825-844)
Rhodri Fawr (844-878)
Anarawd ap Rhodri (878-916)
Idwal Foel (916-942)
Hywel Dda a grandson of Anarawd ap Rhodri but ruler of Deheubarth kills Idwal Foel and unites Deheubarth with Gwynedd]
Hywel Dda (942-950)
On the death of Hywel Dda the sons of Idwal Foel restores the main line of Merfyn Frych
Ieuaf ab Idwal Foe (950-969) (joint ruler)
Iago ab Idwal Foel (950-974, 974-979) (joint ruler)
Hywel ab Ieuaf (979-985)
Cadwallon ab Ieuaf (985-986)
Maredudd ab Owain a grandson of Hywel Dda follows in his footsteps and unites Deheubarth with Gwynedd
Maredudd ab Owain (986-999)
On the death of Maredudd ab Owain the main line of Merfyn Frych is restored
Cynan ap Hywel (999-1005)
The House of Llywelyn ap Seisyll
Llywelyn ap Seisyll (1005-1023)
The House of Merfyn Frych (restored)
Iago ab Idwal ap Meurig (1023-1039)
The House of Llywelyn ap Seisyll (restored)
Gruffudd ap Llywelyn (1039-1063)
Bleddyn ap Cynfyn (1063-1075)
Rhiwallon ap Cynfyn (1063-1070) joint ruler with his brother
Trahaern ap Caradog (1075-1081)
The House of Gruffudd ap Cynan
Gruffyud ap Cynan (1081)
Gwynedd occupied by the Norman Robert of Rhuddlan
Gruffudd ap Cynan (1099-1137)
Owain Gwynedd (1137-1170)
Hywel ab Owain (1170)
Maelgwn ab Owain (1170-1174)
Dafydd ab Owain (1174-1194)
Rhodri ab Owain (1194-1195)
Llywelyn Fawr (1194-1240)
Dafydd ap Llywelyn (1240-1246)
Llywelyn ap Grufudd (1246-1282)
Dafydd ap Gruffudd (1282-1283)