The rules of the three dramatic unities in French drama date undoubtedly from the Silvanire of Mairet, which appeared in 1631, with a preface including a discussion of the three rules. Alexandre Hardy, who before Mairet is the most conspicuous French dramatist and really the only one of any special merit, was apparently not familiar with these rules, and Corneille is said never to have heard of them before 1631. An edition of Tyr et Sidon, dated 1628, has a preface written by Francois Ogier, a scholarly man and friend of Balzac. He opposed the dramatic unities decidedly and even thus early we have a beginning of that discussion which later so disturbed the peace of the French literary mind. Chapelain took up the cudgels in favor of the unities, and even declared that the presentation of a play should not exceed in hours the actual number that the events would require.
Aldrich, Helen J., "The Influence of the Three Dramatic Unities Upon the French Drama From the Cid to Hernani" (1909). University Libraries Digitized Theses 189x-20xx. 158.