Dictionary of Medieval Names
from European Sources

Theresa f. Of uncertain origin, but possibly from Greek θερίζω 'to harvest'.

The name of a 12th-13th C Portuguese saint and queen of Leon, and a 16th C Spanish saint.

The name did not spread outside of the Iberian peninsula until the 16th century, with the veneration of Saint Theresa of Avila.

Portugal
Latin
1096 Taraxea (abl) PHGCRP-I no. 1, Taraxia (nom) ibid. no. 1; 1121 Tarasia (abl) ibid. no. 2, Tharasia (abl) ibid. no. 2; 1179x1211 Tarasiae (gen) ibid. no. 5; 1189 Therasia (abl) ibid. no. 9; 1190 Tharasia (nom) ibid. no. 8; 1209 Tarasie (gen) ibid. no. 10, Tarasiæ (dat) ibid. no. 10, Taresia (nom) ibid. no. 10, Tharasiæ (dat) ibid. no. 10; 1269 Tarasia (nom) ibid. no. 11, Tarasie (dat) ibid. no. 11, Tarasiæ (gen) ibid. no. 11
Spain
Catalan
1510 Tareza valencia1510 4303, Teresa ibid. 4162
Spanish
1319 Tareisa deMoxo, Teresa ibid.; 1328 Tereysa ibid.; 1332 Tereysa ibid.; 1334 Teresa ibid.; 1336 Tereysa ibid.; 1348 Tereysa ibid.; 1496 Theresa olite1496 p. 185; 1575 Teresa Catalogo-5.2 3816; 1576 Teresa ibid. 3989
Cite as: S.L. Uckelman. "Theresa". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Theresa.