There’s a meme (due to www.abbeytournament.com) that’s been circulating around Facebook sporadically recently, allowing people to generate their “medieval name” according to their birthday. You’ve probably seen it:
The first time it came up in a group that a couple DMNES staff are members of — a group not devoted to either the Middle Ages or to names — one editorial assistant put out a cry for “HALP”, and another swooped in with documentation. Now every time that meme comes around, we’re reminded of that thread, and finally decided to make a blog post out of it!
So, how medieval is “Your Medieval Name”? Actually, pretty medieval!
The feminine names are almost all good solid choices for late medieval England or France:
- Milicent – Yes, medieval!
- Alianor – Yes, medieval!
- Ellyn – Yes, medieval!
- Sybbyl – Yes, medieval!
- Jacquelyn – Yes, medieval!
- Catherine – Yes, medieval!
- Elizabeth – Yes, medieval!
- Thea – Possibly medieval but we’ve not found any evidence for it yet.
- Lucilla – Sort of medieval: R.G. Collingwood and R.P. Wright, The Roman Inscriptions of Britain I: Inscriptions on Stone — Epigraphic Indexes (Gloucester: Alan Sutton, 1983), RIB 1288 and 1271, note one Iulia Lucilla in a first- to fourth-century British inscription (in this name, Lucilla appears as a cognomen), and another Romano-British inscription mentioning a woman known only as [L]ucilla.
- Mary – Yes, medieval!
- Arabella – Yes, medieval: E.G. Withycombe, The Oxford Dictionary of English Christian Names, 3rd ed. (Oxford: Oxford University Press, 1988). s.n. Arabel(la) has a 13th C Latin example of the name.
- Muriel – Yes, medieval: A variety of forms can be found in P.H. Reaney & R.M. Wilson, A Dictionary of English Surnames (London: Routledge, 1991).
- Isabel – Yes, medieval!
- Angmar – Um, no.
- Isolde – Yes, medieval!
- Eleanor – Yes, medieval!
- Josselyn – Yes, medieval, but not as a feminine name.
- Margaret – Yes, medieval!
- Luanda – Um, no.
- Ariana – Not medieval: It’s a modern Italian form of the Greek name Ariadne, found in mythology, and in the Greek and Byzantine empires.
- Clarice – Yes, medieval!
- Idla – Possibly medieval. It appears that this googlebook has a Polish example of the name, but we have not been able to get more than a snippet view, to be able to confirm the date and context.
- Claire – Yes, medieval!
- Rya – Um, no.
- Joan – Yes, medieval!
- Clemence – Yes, medieval!
- Morgaine – Yes, medieval, but only used in literature, and not by real people.
- Edith – Yes, medieval!
- Nerida – Definitely not.
- Ysmay – Yes, medieval: Withycombe (op. cit.) has an example of this spelling.
The masculine names don’t fare quite so well.
- Ulric – Yes, medieval!
- Baird – Yes, medieval, but only as a surname, not as a given name. It is derived from Old French baiard or baiard ‘bay-colored’.
- Henry – Yes, medieval!
- Oliver – Yes, medieval
- Fraden – Possibly medieval, but only as a surname, not as a given name.
- John – Yes, medieval!
- Geoffrey – Yes, medieval!
- Francis – Yes, medieval!
- Simon – Yes, medieval!
- Fendel – Not medieval to my knowledge, either as a given name or a surname.
- Frederick – Yes, medieval!
- Thomas – Yes, medieval!
- Arthur – Yes, medieval!
- Cassius – More Roman than medieval.
- Richard – Yes, medieval!
- Matthew – Yes, medieval!
- Charles – Yes, medieval!
- Reynard – Yes, medieval!
- Favian – Sort of medieval, if you take it as a variant of Fabian.
- Philip – Yes, medieval!
- Zoricus – Not medieval to our knowledge, but it could possibly turn up at some point in future research.
- Carac – Not medieval
- Sadon – Not medieval
- Alistair – Medieval, but not as the nominative form of the name, only as the genitive.
- Caine – Yes, medieval, but only as a surname, not as a given name.
- Gawain – Yes, medieval!
- Godfrey – Yes, medieval!
- Mericus – More Roman than medieval.
- Rowley – Yes, medieval, but only as a surname, not as a given name.
- Brom – Yes, medieval, but only as a surname, not as a given name.
- Cornell – Yes, medieval, but only as a surname, not as a given name.
All the surnames are fine for 14th-16th C English, except these:
- Cabrera – This is Spanish, and would only have been used by women; the masculine form is Cabrero.
- Coastillon – Not quite sure what this is but it looks like a misspelling of some French place name.
Dictionary of Medieval Names from European Sources 
“Cabrera” is certainly the usual form of a Spanish surname, well attested since the 11th century as “X de Cabrera” (Lat. “de Capraria”). It’s toponymic rather than occupational, so there’s no reason for it to change. (Though “Cabrero”, presumably occupational, exists too in the 15-16th centuries at least.)