Giovanni Guerra (1544–1618) was an Italian draughtsman and painter from Modena who worked in Rome, where he probably arrived in 1562, though he was not documented until 1583, when he frescoed three friezes of allegorical figures in the Palazzetto Cenci, a modest project for a patron who was not very prestigious.
For Cardinal Montalto he dedicated an elaborate composition of the Mystic Terrestrial Paradise (paradiso terrestre mistico), which he had engraved with verses composed for the occasion; decorations from the Sala Grande of the Palazzo alle Terme of the Villa Montalto are also attributed to Guerra: on 24 April 1585 the Cardinal was elected to the papacy as Sixtus V. In 1586 Guerra received the important commission, the first project of Sixtus, to fresco the staircase that connects the Sistine Chapel in the Vatican Palace with St. Peter's Basilica. In this large undertaking he was associated from the start of the following year with the experienced Cesare Nebbia, and the partners continued to control the expanding team of painters in the vast decorations for Sixtus V, notably in the Salone Sistino of the Vatican Library (completed in 1589), where they provided designs and supervision for a multitude of assistants, in a project that Sidney J. Freedberg dismisses as "prosy humanistic subject matter in a flat academic style". Guerra did less painting as the project unrolled, concentrating on providing the other artists with designs, his strong point, for his coloring was weak, according to his first biographer, F. Forciroli. He developed a reputation as an inventor of designs, such as the series of drawings demonstrating the story of Judith, now in the Avery Library, Columbia University, which another hand has referred to this pittore erudito
Guerra provided drawings for Cesare Ripa's Iconologia (1593) and further drawings for its second, expanded Roman edition (1603), which remained in active use by painters and designers for the decorative arts for more than a century. His own little volume of engraved emblems, Varii Emblemi hierogliphici, he signed as Pittore e Invent. More than three hundred drawings by him are conserved in the Musée du Louvre and the École nationale supérieure des Beaux-Arts, Paris.
- According to a vita written by F. Forciroli, c. 1618-20, noted in Stefano Pierguidi, "Giovanni Guerra and the Illustrations to Ripa's Iconologia" Journal of the Warburg and Courtauld Institutes 61 (1998, pp. 158-175) p. 160 and note 10.
- The sixteenth-century Palazzetto Cenci, facing via del Arco de' Cenci, forms part of the complex of structures called the Palazzo Cenci (TCI, Roma e Dintorni 1965:250).
- Pierguidi 1998:160; the ancient Roman family was to become suddenly notorious in 1599 with the sensational trial for murder of Beatrice Cenci.
- Mario Bevilacqua, "Della decorazione della Sala Grande del Palazzo alle Terme della Villa Montalto" in M. Fagiolo and M.L. Madonna, eds., Sisto V, i: Roma e il Lazio (Rome) 1993:724-26, noted in Pierguidi 1998:164 note 31.
- Nebbia, with Girolamo Muziano, had frescoed the Vatican's Galleria delle Carte Geographiche (completed in 1580) for Pope Gregory XIII.
- Touring Club Italiano, Roma e Dintorni 1965:540 notes Paul Brill Ventura Salimbeni, Giovanni Battista Ricci, Andrea Lilio, Orazio Gentileschi, Giovanni Battista Pozzo and Avanzino Nucci.
- Freedberg, Painting in Italy 1500-1600 3rd ed. 1993:656.
- "Erudite painter"; noted by Pierguidi 1998:161
- Pierguidi 1998:158-175.