Ruler · 974 – 1023

Llywelyn ap Seisyll

Lived 974 – 1023; monarch. King of Gwynedd of Kingdom of Gwynedd, 1018 – 1023.

For the full story, the article on Wikipedia (CC BY-SA 4.0); this page holds what the record says of the reign.

Lived: 974 – 1023; 49 years
In office: 5 years; one reign
Lines: 1; Kingdom of Gwynedd
Left it: died in office; read off the dates alone

King of Gwynedd

Kingdom of Gwynedd · the 28th of 40 dated reigns · 450 – 1240

24 before

Cadwallon ab Ieuaf985 – 986

Cynan ap Hywel999 – 1003

Aeddan ap Blegywryd1005 – 1018

Llywelyn ap Seisyll1018 – 1023

Iago ab Idwal ap Meurig1023 – 1039

Gruffudd ap Llywelyn1039 – 1063

Rhiwallon ap Cynfyn1063 – 1069

9 after

killed, executed or dead in battledied in officeleft alive by a regular roadending not on recorda second row: a reign that began before the last had ended — rival claimants, or a shared thronethis entry

Reigned 1018 – 1023 · 5 years · came to it aged 44

Left it: died in officeread off the dates alone: the term ends in 1023, the year they died

Open in the atlas

Llywelyn ap Seisyll in the atlas: the article, every line they sat in, and the map in their years.
Analyse the succession of Kingdom of Gwynedd: every reign, how each ended, and the numbers over them.
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Wikidata Q953828 (CC0) · the reigns from Wikidata's P39 terms, the rulers' own articles read by grammar (sentences quoted above, CC BY-SA 4.0) and Kokkonen & Sundell where they code the line · data built 2026-10-06 · Pastlas v2.9.1, by Oleh Voronko. The published atlas and its data are for non-commercial use.