As in the commentary on the Rambam’s Sefer HaMitzvot. Do we know this person’s identity? Or even when this person lived?
R. David Conforte identifies (Korei Hadorot 28a) the author of Megillat Esther as R. Isaac de Leon, a student of R. Isaac Kampaton. R. Hayyim Joseph David Azulai, however, (Shem Hagedolim Vol. I entry 333 for the letter Yod) raised several arguments against this identification and concluded that the author of Megillat Esther was R. Isaac Leon (where Leon was his name rather than his city of origin) the author of a halachic work printed in Rome in 1547.