He notably wrote the manifesto of the group: Défense et illustration de la langue française, which aimed at promoting French as an artistic language, equal to Greek and Latin.
Both his parents died while he was still a child, and he was left to the guardianship of his elder brother, René du Bellay, who neglected his education, leaving him to run wild at La Turmelière.
When he was twenty-three, however, he received permission to study law at the University of Poitiers, no doubt with a view to his obtaining preferment through his kinsman the Cardinal Jean du Bellay.
There too he probably met Jacques Peletier du Mans, who had published a translation of the Ars Poetica of Horace, with a preface in which much of the program advocated later by La Pléiade is to be found in outline.
[3] While Ronsard and Jean-Antoine de Baïf were most influenced by Greek models, du Bellay was more especially a Latinist, and perhaps his preference for a language so nearly connected with his own had some part in determining the more national and familiar note of his poetry.
In 1548 appeared the Art poétique of Thomas Sébillet, who enunciated many of the ideas that Ronsard and his followers had at heart, though with essential differences in the point of view, since he held up as models Clément Marot and his disciples.
This book (inspired in part by Sperone Speroni's Dialogo delle lingue, 1542) was the expression of the literary principles of the Pléiade as a whole, but although Ronsard was the chosen leader, its redaction was entrusted to du Bellay.
Du Bellay maintained that the French language as it was then constituted was too poor to serve as a medium for the higher forms of poetry, but he contended that by proper cultivation it might be brought on a level with the classical tongues.
[5] Du Bellay replied to his various assailants in a preface to the second edition (1550) of his sonnet sequence Olive, with which he also published two polemical poems, the Musagnaeomachie, and an ode addressed to Ronsard, Contre les envieux fioles.
Olive has been supposed to be an anagram for the name of a Mlle Viole, but there is little evidence of real passion in the poems, and they may perhaps be regarded as a Petrarchan exercise, especially as, in the second edition, the dedication to his lady is exchanged for one to Marguerite de Valois, sister of Henry II.
[6] The Nouvelle Manière is believed to be directed at Pierre de Paschal, who was elected as royal historiographer, and who had promised to write Latin biographies of the great, but who in fact never wrote anything of the sort.
[6] A long and eloquent Discours au roi (detailing the duties of a prince, and translated from a Latin original written by Michel de l'Hôpital, now lost) was dedicated to Francis II in 1559, and is said to have secured for the poet a tardy pension, although it was not published until 1567, after his death.
[6] His remains were reportedly identified in 2024 in a lead coffin found in April 2022 during excavations carried out by the National Institute for Preventive Archaeological Research (Inrap) after the Cathedral fire in 2019.
Traces of bone tuberculosis and chronic meningitis found on the skeleton, of which the poet showed symptoms in the last years of his life, leave little doubt as to the identity of the deceased, according to Éric Crubézy, a doctor and professor of anthropology at the Toulouse III - Paul Sabatier University.
The chief source of his biography is his own poetry, especially the Latin elegy addressed to Jean de Morel, "Elegia ad Janum Morellum Ebredunensem, Pytadem suum," printed with a volume of Xenia (Paris, 1569).