The ring reads “ANIMA DVLCIS VIVAS MECV” - “May you live with me sweet soul”

“One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them.”

A few tidbits:

Spelling “mecu” for “mecum” (with me) might sound weird, but by the fourth century odds are Latin nasal vowels already fell into disuse. It was probably pronounced [me:kũ:] in Classical times, [meku] by the time this ring was forged. Romance languages consistently ditched that nasal; see e.g. Italian “meco” or Spanish “conmigo” (lit. “with me-with”).

Interesting usage of the subjunctive (uiuas) instead of the imperative (uiua). Both would be grammatically correct here, and convey roughly the same thing, but I guess the imperative would sound a bit too pushy; more like an order than like a hope or desire.

Cheesy lines comparing your loved one with sweets are really, really old. Plautus’ Bacchides (from 190 BCE) already show:

cor meum, spes mea, / mel meum, suavitudo, cibus, gaudium. / sine te amem.
My heart, my hope, / my honey, delight, sustenance, joy. / allow (me) to love you.

And this text is like, half a millennium older than the ring! (Those cheesy lines are still alive and kicking in Romance-speaking cultures, by the way. I cringe a bit when I see a couple calling each other “docinho” [little sweet], but it isn’t like I didn’t do the same in my late teens / early adulthood.)