Having taught himself Latin and Greek, he studied law under Arnaud du Ferrièr, then professor at Toulouse, and rapidly gained a great reputation as a lecturer on Justinian.

François Douaren (Franciscus Duarenus), who also held a professorship at Bourges, stirred up the students against the new professor, and Cujas was glad to accept an invitation he had received to the University of Valence.

In 1573 King Charles IX of France appointed Cujas counsellor to the parlement of Grenoble, and in the following year a pension was bestowed on him by Henry III.

A year later, he finally took up residence at Bourges, where he remained until his death in 1590, in spite of a handsome offer made him by pope Gregory XIII in 1584 to attract him to Bologna.

[1] His emendations, of which a large number were published under the title of Observationes et emendationes, were not confined to lawbooks, but extended to many of the Latin and Greek classical authors.

In the Paratitla, or summaries which he made of the Digest, and particularly of the Code of Justinian, he condensed into short axioms the elementary principles of law, and gave definitions remarkable for their clarity and precision.