This article considers the attribution to Jerome Bolsec of a tract lampooning John Calvin, and composed in verse under the pseudonym of 'Pasquin Romain.' The sole surviving copy is in the Bibliothëque nationale de France. Entitled Le double des lettres envoyees à Passevent Parisien, par le Noble et excellent Pasquin Romain, contenant en vérité la vie de Jehan Calvin [Copy of letters sent to Passevent Parisian by the noble and excellent Pasquin Romain, containing the true life of John Calvini, the pamphlet was published in Paris in 1556 by Pierrre Gaultier. External textual evidence, contemporary witnesses and a thorough comparison of the pamphlet with Bolsec's later, famous anti-Calvin bibliography, Histoire de la vie…deJean Calvin (1577), enable the authorship of the 1556 satirical tract to he identified. Its rediscovery allows one to antedate by at least twenty years the beginnings of Bolsec's anti-Geneva polemics. At that time, he had not yet abandoned the Reformed faith, while figuring among the precursors of anti-Calvinist propaganda that was waxing in heterodox French and transalpine circles. Moreover, the pamphlet is a rare example of the religious commitment and behaviour of a nonconformist of genuine faith who can subscribe neither to the Roman Church nor to the growing orthodoxy of the Genevan Church. [ABSTRACT FROM AUTHOR]