Medieval Spanish variant of Isabel, from Hebrew Elisheba meaning 'God is my oath.'
Ysabel is one of the most romantic of the Elizabeth variants, carrying the full weight of that ancient Hebrew name — Elisheba, meaning "my God is an oath" or "pledged to God" — through a medieval Iberian filter. From the Hebrew, the name traveled into Greek as Elisavet, then Latin as Elisabeth, and in the Provençal and early Castilian tradition it was softened and reshaped into Ysabel and Isabel. The opening "Y" is not an affectation but a genuine archaic spelling, found in medieval manuscripts and royal registers at a time when the distinction between I and Y was fluid in Romance languages.
The name belongs to queens. Isabella I of Castile — whose name appears in contemporary documents variously as Ysabel, Isabel, and Isabella — commissioned Columbus's voyage and co-founded the Spanish state. Isabella II of Spain reigned through a turbulent nineteenth century.
The name also appears in English literary tradition through the poetry of John Keats, whose haunting "Isabella; or, The Pot of Basil" gives the name a lush, tragic Gothic resonance that has never fully faded. As a given name in the modern era, Ysabel occupies a narrow and distinguished niche. Parents who choose this spelling over Isabella or Isabel are usually reaching deliberately for its medieval texture — it looks like a name lifted from an illuminated manuscript, poised between the ancient and the poetic. It has been used by fantasy authors and historical novelists as a byword for a certain kind of aristocratic, timeless femininity, and it functions today as a name for those who want the warm familiarity of Isabel with a spine of genuine historical strangeness.