Guithelin
{{Infobox royalty
| name = Guithelin
| succession = King of Britain
| predecessor = Gurguit Barbtruc
| successor = Marcia (Regent);
Sisillius II
| spouse = Marcia
| issue = Sisillius I
| father = Gurguit Barbtruc
}}
Guithelin was a legendary king of the Britons as accounted by Geoffrey of Monmouth. He became king after the death of Gurguit Barbtruc[http://www.monarchie-noblesse.net/angleterre/bretons/bretons.htm Monarchie Nobelesse website, Bretons] and reigned approximately 379 BC.
He ruled liberally and temperately for his life. His Queen consort was an artisan and noblewoman named Marcia; when he died, his wife took over the government as regent for their son, Sisillius II.[https://sacred-texts.com/neu/eng/gem/gem04.htm Sacred Texts website, Histories of the Kings of Britain (Book III), by Geoffry of Monmouth, tr. by Sebastian Evans, (1904)]
References
{{reflist}}
{{s-start}}
{{s-reg | leg }}
{{s-bef | before = Gurguit Barbtruc }}
{{s-ttl | title = King of Britain }}
{{s-aft | after = Marcia (Regent);
Sisillius II }}
{{s-end}}
{{Geoffrey of Monmouth}}