What is "leonius"

Leonius may refer to:

• Léonin ( fl. 1150s — d. ? 1201), the first known significant composer of polyphonic organum;
• the author of a versified Historia Sacra found in a manuscript of the Bibliothèque Nationale in Paris (see Leonine verse);
• the probably apocryphal inventor of Leonine verse, if different from either or both of the preceding two persons.

Leonius was the Dean of Wells during 1213.