Jose Francisco De Isla, a Spanish author, born in Segovia in 1703, died in Bologna in 1781. He early became famous as a Jesuit preacher and a satirical poet. His first works were directed against an extravagant religious festival at Salamanca in 1727, and a royal pageant at Pampeluna in 1746; but he managed his sarcasm so adroitly that the authorities of the latter city at first regarded his effusion as complimentary, though subsequently he left the city, and probably was expelled. His published sermons (1729-'54) show a marked improvement upon the prevailing tone of the itinerant friars, and he reformed this effectively by his celebrated romance Historia del fa-moso predicador Fray Gerundio de Campazas. The first volume, printed without his knowledge in 1758, was eagerly bought up; the derisive epithet of Fray Gerundio, henceforward applied to vulgar preachers, put an end to their vocation; but the government was obliged to withdraw the license for its publication in obedience to the clamors of the clergy. The inquisition condemned the book in 1760, but did not molest the author, who was protected by his increasing popularity.

The violent expulsion of his order in 1767, requiring his sudden departure, gave a shock to his health from which he never recovered, and he spent the rest of his life in Bologna. The manuscript of his second volume having reached London', Baretti published it in English (1772); and complete Spanish editions soon appeared at Bayonne and elsewhere, Isla's friend Francisco Lobon de Salazar, a priest at Villagarcia, in whose house he had written the work, appearing as the author in the earliest and in some of the later editions to elude the censorship. . In 1813 the work was published in Madrid in 4 vols.; and though again interdicted next year, it continued to have a large circulation. Ticknor finds in its plan some resemblance to "Don Quixote," and in its execution he compares it to Rabelais. Isla's works also include Cicero, a satirical poem in 16 cantos. Permission to print it was denied, and the manuscript was presented in 1844 to the library of the Athenaeum of Boston, Mass., together with some of Isla's autograph letters.

His letters to his sisters and brother-in-law, Cartas familiares, were published posthumously in 6 vols., 1785-'6. - See Vida de J. F. de Islay by J. I. de Salas (Madrid, 1803).