Dictionary of Medieval Names
from European Sources

Isaiah m. Ancient Greek Ἠσαΐας from Hebrew יְשַׁעְיָהוּ 'Yahweh is salvation'.

The name of an Old Testament prophet, an 8th C Catholicos of Armenia, and an 11th C Russian saint. Wycliffite Bible (1395): Isaie, Ysaie.

France
Middle French
1560 Isaïe RegPCC-1 p. 1; 1561 Esaïe ibid. p. 5; 1564 Ysaye ibid. p. 56; 1566 Esaye ibid. p. 208; 1567 Esaye ibid. p. 322; 1570 Esaïe ibid. p. 431
Cite as: S.L. Uckelman. "Isaiah". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Isaiah.