Dictionary of Medieval Names
from European Sources

Ithel m. Old Breton, Middle Welsh iud 'prince, lord' Old Breton, Middle Welsh hael 'generous, noble'.

The name of a 6th C prince of Armorica and a 6th-7th C prince of Dumnonia.

The Breton form Judhael or Iudhael developed into Jouel or Jowel in England, which in turn developed into forms which are indistinguishable from forms of Joel.

France
Latin
1101x1129 Judallus (nom) CartStPC XVI
Wales
Latin
1216xc1226 Ithael (acc) Pryce-1st no. 16; 1247 Itello (abl) ArchCambIII p. 228; 1360 Itheli (dat) ibid. p. 165; 1452 Ithel (nom) ibid. p. 72; 1453 Ithel (nom) ibid. p. 69, Ithil (nom) ibid. p. 70; 1455 Ithel (nom) ibid. p. 72; 1456 Ithell (nom) ibid. p. 258; 1497 Ithell (nom) ibid. p. 68
Welsh
1544 Ithel RegCon1 p. 7
Cite as: S.L. Uckelman. "Ithel". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Ithel.