Welsh or Old French form of Alice, from Germanic 'adal' meaning 'noble.'
Alys is the medieval Welsh and Old French spelling of Alice, which itself descends from the Old High German Adalheidis — a compound of adal (noble) and heid (kind or type), meaning roughly "of noble kind." The simplified form Aalis passed through Norman French into England after 1066, becoming Alice in its anglicized form and Alys in Welsh-speaking communities, where it has remained in continuous use for nearly a thousand years. That extra layer of Welsh identity gives Alys something Alice lacks: a sense of place, a geographic soul.
In medieval literature, the name appears memorably in Chaucer's Canterbury Tales, where the Wife of Bath — one of the most vivid and defiant characters in English literature — bears the name Alisoun, a close relative of Alys. The name was enormously popular across medieval Europe, borne by queens, saints, and commoners alike. Lewis Carroll's Alice's Adventures in Wonderland (1865) reinvigorated the entire family of names in the English-speaking world, though the Welsh Alys had never really needed the help.
The spelling Alys has gained admirers in the contemporary era for exactly the reasons medieval spellings often do: it signals education, historical awareness, and a gentle resistance to the expected. It reads as distinctive without being invented, classical without feeling stuffy. In Wales today it remains a living name rather than an antiquarian curiosity, and internationally it appeals to parents who want the familiar music of Alice dressed in something older and slightly more rare.