This article is about the medieval kingdom of Gwynedd. For the modern administrative county of Wales, see Gwynedd.

Gwynedd was one of the kingdoms or principalities of medieval Wales. Covering an area in the north-west of the country around Snowdonia and including the island of Anglesey, its rulers—such as Owain Gwynedd, Llywelyn the Great and Llywelyn the Last—usually held ascendancy over their rivals. The region's geography made it difficult for English kings to impose their will on the local rulers.

Gwynedd covered the territory of the Ordovices, but tradition traced the kingdom's foundation to Cunedda, who migrated with his sons and followers from what is now southern Scotland. The territory was originally known as Venedotia, a name which mutated to Gwynedd over the next two centuries. The heart of Gwynedd was originally at Deganwy , but later moved to Anglesey.

During the period of the Norman conquest of Wales, between the years 1066 and 1282, Gwynedd was a centre of national resistance, the last stronghold of the native Welsh princes against the kings of England.

As the Welsh "dd" is pronounced like the English "th", "Gwynedd" is pronounced like (and is a likely source of) the modern personal name "Gwyneth."

List of Kings/Princes

• Cunedda Wledig ap Edern (Cunedda the Imperator) (c.450-c.460)
• Einion Yrth ap Cunedda (Einion the Impetuous) (c.470-c.480)
• Cadwallon Lawhir ap Einion (Cadwallon Long Hand) (c.500-c.534)
• Maelgwn Hir ap Cadwallon (Maelgwn the Tall) (c.520-c.549)
• Rhun Hir ap Maelgwn (Rhun the Tall) (c.549-c.580)
• Beli ap Rhun (c.580-c.599)
• Iago ap Beli (c.599-c.613)
• Cadfan ap Iago (c.613-c.625)
• Cadwallon ap Cadfan (c.620-634)
• Cadfael Cadomedd ap Cynfeddw (Cadfael the Battle-Shirker) (634-c.655)
• Cadwaladr Fendigaid ap Cadwallon (Cadwallader the Blessed) (c.655-c.682)
• Idwal Iwrch ap Cadwaladr (Idwal Roebuck) (c.682-c.720)
• Rhodri Molwynog ap Idwal (Rhodri the Bald and Gray) (c.720-c.754)
• Caradog ap Meirion (c.754-c.798)
• Cynan Dindaethwy ap Rhodri (c.798-816)
• Hywel Farf-Fehinog ab Caradog (Howell Greasy-Beard) (814-825)
• Merfyn Frych ap Gwriad (Merfyn the Freckled) (825-844)
• Rhodri Mawr ap Merfyn (Rhodri the Great) (844-878)
• Anarawd ap Rhodri (878-916)
• Idwal Foel ap Anarawd (Idwal the Bald) (916-942)
• Hywel Dda ap Cadell (Howell the Good) (942-950)
• Iago ab Idwal (950-979)
• Ieuaf ab Idwal (950-969)
• Hywel ap Ieuaf (974-985)
• Cadwallon ap Ieuaf (985-986)
• Maredudd ap Owain (986-999)
• Cynan ap Hywel (999-1005)
• Llywelyn ap Seisyll (1005-1023)
• Iago ap Idwal ap Meurig (1023-1039)
• Gruffydd ap Llywelyn (1039-1063)
• Bleddyn ap Cynfyn (1063-1075)
• Rhiwallon ap Cynfyn (1063-1070)
• Trahern ap Caradog (1075-1081)
• Gruffydd ap Cynan (1081-1137)
• Owain Gwynedd ap Gruffydd (1137-1170)
• Maelgwn ab Owain (1170-1173)
• Dafydd ab Owain Gwynedd (1170-1195) (in the east)
• Rhodri ab Owain Gwynedd (1170-1190) (in the west)
• Llywelyn Fawr ap Iorwerth (Llywelyn the Great) (1195-1240)
• Dafydd ap Llywelyn (1240-1246)
• Llywelyn Ein Llyw Olaf ap Gruffydd (Llywelyn the Last) (1246-1282)
• Owain Goch ap Gruffydd (1246-1255)
• Dafydd ap Gruffydd (1282-1283)

Following the death of Llywelyn ap Gruffydd in 1282, and of his brother Dafydd ap Gruffydd the following year, eight centuries of independent rule by the house of Gwynedd came to an end, and the kingdom, which had long been one of the final holdouts to total English domination of Wales, was absorbed in the kingdom of Edward I. An exception can be made for the Gwynedd-based rebellion of

• Owain Glyndŵr (1359-c.1416)