Owing to the wars which agitated Bulgaria in the 14th century, Mosconi left his native country about 1360.
He was in Chios and Cyprus, in Négropont (where he became the pupil of Shemariah b. Elijah al-Iḳriṭi), in Laodicea, and later in Egypt (where he studied under Obadiah Miẓri, to whom he owed "the greatest part of his learning").
Mosconi was well versed in philosophical works, both Hebrew and Arabic; but, having a predilection for metaphysics, he occupied himself particularly with Ibn Ezra's commentary on the Pentateuch, on which he wrote a supercommentary.
Simultaneously with his supercommentary, Mosconi began to write other treatises, e.g.: En Gedi, an explanation of certain metaphysical passages disseminated in different works; Reaḥ Niḥoaḥ, a treatise on sacrifices; Ṭa'ame ha-Mibṭa, on grammar—all these works being left unfinished on account of the persecutions which he underwent.
[2] Steinschneider[3] thinks that the Moses Mosconi mentioned by Moses Begi in his Ohel Mosheh as having written against the Karaite Aaron b. Elijah is identical with Judah Leon Mosconi, whose name was incorrectly given by Begi.