From Greek 'eustakhys' meaning fruitful or productive; borne by several early saints.
Eustace descends from the Greek *Eustachios* (Εὐστάχιος), a name composed of *eu* ("good, well") and *stachys* ("grapes" or "grain ear"), yielding the sense of "fruitful," "good harvest," or "one who stands firm in good fortune." The name entered the Latin Christian world primarily through Saint Eustace, a Roman general of the second century who, according to hagiography, converted to Christianity after seeing a vision of a crucifix between a stag's antlers while hunting. His story — a mirror of Saint Hubert's legend — made him patron of hunters and those in difficult situations, and his feast day spread the name across medieval Europe.
Norman knights carried Eustace into England after 1066, and it became a recognizable medieval English name, borne by several notable figures including Eustace, Count of Boulogne, who fought at Hastings. In English literature the name took on a slightly pompous, fussy character over time — a perception cemented by C. S.
Lewis's *The Voyage of the Dawn Treader*, where Eustace Clarence Scrubb is introduced as a self-important and disagreeable boy who must be transformed by adventure. Lewis's Eustace ultimately becomes one of Narnia's heroes, rehabilitating the name somewhat with a story of genuine growth. Eustace is rare enough today to feel genuinely distinctive without being invented.
It sits in the same family as Barnaby, Alistair, and Crispin — names with deep medieval English roots that fell out of fashion in the twentieth century and are now ripe for rediscovery. Its built-in nickname, Stace, softens it considerably for everyday use.