Dictionary of Medieval Names
from European Sources

Eustace m. Greek Εὔσταχυς 'fruitful, fecund'.

The name of three early saints, including a 2nd C martyr.

The name was rare outside England and France.

Belgium
Latin
c1130 Eustachius (nom) CartStBert 12
Dutch
1597x1598 Eustaes BoonenGes p. 340
Brabant
Latin
1312 Eustachius (nom) JeanIII p. 42, Eustassius (nom) ibid. p. 43, Eustatius (nom) ibid. p. 37
England
Latin
1183 Eustacii (gen) BoldonBuke p. 3; 1185x1186 Eustacio (abl) PR-XXXVI p. 15, Eustacius (nom) ibid. p. 15; 1222 Eustachii (gen) StPaulDom p. 19, Eustachius (nom) ibid. p. 14; 1256 Eustacii (gen) EARNb p. 5; 1279–80 Eustacius (nom) WaHR-SK p. 36
Early Modern English
1530 Ewstace PP-HenV p. 15; 1574/5 Ustice RegBisham p. 3; 1579 Ustice ibid. p. 4; 1582 Ustis ibid. p. 4; 1586 Eustace DEmar-vol2 p. 13; 1593 Eustace ibid. p. 27
France
Latin
1079x1101 Eustachio (abl) CartStPC XXXVII; a1089x1101 Eustachius (nom) ibid. XXXIX; 1090x1101 Eustachius (nom) ibid. XLIII; 1093 Eustachii (gen) ibid. VI; 1101x1129 Eustachio (abl) ibid. XXIII; 1115 Eustachius (nom) CartNDJosaphat VI; 1120 Eustachius (nom) ibid. VIII; 1123 Eustachii (gen) ibid. XII; c1140 Eustachium (acc) CartNDdOurscamp LXXXIII; c1160 Eustachii (gen) ibid. XVI; 1168 Eustacius (nom) clairvaux-12thc 134; 1194 Eustachii (gen) CartNDdOurscamp CLVI; 1208 Eustachius (nom) ibid. LXXVI; 1257 Eustachius (nom) ArrestReg-volI IX, Pentecost; 1259 Eustachius (nom) ibid. XXII, Pentecost; 1301 Estacius (nom) MemPic-vol17 p. 218, Eustachii (gen) ibid. p. 202, Eustachius (nom) ibid. p. 202, Eustacius (nom) ibid. p. 226; 1378 Eustachio (dat) hanquetvol1 237, Eustacio (dat) ibid. 538, Eustacius (nom) ibid. 1761
Old French
1292 Estace (obl) MemBret-I 1102; 1327 Eustace MemDocMan-2 p. 180, Eustache ibid. p. 180
Middle French
1388 Eustace thierry; 1418 Eustace HGParis p. 383, Eustache DdB1418 p. 200, Eustasse HGParis p. 376; 1421 Eustace favier 845; 1493 Eustace MSR1838 p. 379; 1555 Eustace HistHdVParis no. 25; 1561 Eustace RegPCC-1 p. 2; 1562 Eustace ibid. p. 7; 1563 Eustace ibid. p. 19; 1565 Eustace ibid. p. 191; 1566 Eustace ibid. p. 205; 1567 Eustace ibid. p. 289; 1568 Eustace ibid. p. 384; 1571 Eustace ibid. p. 437
Hungary
Latin
1351 Eustachio (abl) CDH-IX-II III
Cite as: J. Uckelman, S.L. Uckelman. "Eustace". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Eustace.