[2] At first he had only the slender means left him by his father, but later pensions from President Jean-Antoine de Mesmes of the parlement of Paris, the clergy of France, Cardinal Mazarin, and Louis XIV provided him with the necessary leisure and the assistance of a secretary, for his sight was never good, and as early as 1637 he ceased to have the use of his right eye.
[2] Nicolas-Claude Fabri de Peiresc had purchased a manuscript in Cyprus containing the work of Constantine Porphyrogenitus on virtue and vice.
Valois took from it numerous previously unedited fragments of earlier historians, which he published in 1634: Polybii, Diodori Siculi, Nicolai Damasceni, Dionysii Halicarnassii, Appiani, Alexandri, Dionis et Ioannis antiocheni excerpta.
In 1636 he edited Ammiani Marcellini rerum gestarum libri XVIII, with abundant notes which illumined all the history of that period and its institutions, together with two fragments, one from an Origo Constantini (ca.
The text was accompanied by a new Latin translation, scholarly notes and four dissertations (on Donatism, the name Anastasis as applied to the Church of the Holy Sepulchre, the Septuagint, and the Roman Martyrology).
In 1673, he completed his book with Theodoret, Evagrius, and the excerpts from Philostorgius and Theodorus Lector: Socratis, Sozomeni, Theodoreti et Evagrii Historia ecclesiastica.