Due to his bizarre appearance in Rome on Palm Sunday 1484 he has been believed by some scholars to have not actually existed, but this has been contested with other reports that corroborate his eccentricities.
His most notable follower was Lodovico Lazzarelli, an Italian humanist poet and alchemist, who writes his accounts of da Correggio in his Epistola Enoch.
The first account of da Correggio was on 12 November 1481 in Rome, where Lodovico Lazzarelli encountered him as an apocalyptic preacher trying to gain the attention of the pope (Sixtus IV) and the College of Cardinals.
[1] On Palm Sunday, 11 April 1484 da Correggio is reported by Lazzarelli to have been in Rome dressed in rich garments and gold with four servants.
Lazzarelli reports that da Correggio then exits the city of Rome, and returns riding on a white donkey in imitation of Jesus.
Da Correggio places upon the altar his mystical apparel and a paper entitled The Eternal Gospel, knelt to pray, and then left.
"[5] He distributed scrolls that read: "Ego Joannes Mercurius de Corigio, sapientiae angelus Pimanderque in summo ac maximo spiritus Jesu Chrisi excessu, hanc aquam regni pro paucis, sic super omnes magna voce evangelizo.
[13] While da Correggio was originally from a noble family, and he seems to have been wealthy given the lavish and rich garments he wore in Rome in 1484 before he paraded around in imitation of Jesus, he appears to be truly destitute beginning in 1499.
This is appropriate as Carlo Sosenna, a humanist scholar, poet, and magician at the University of Ferrara, writes a commentary on a sonnet attributed to da Correggio.
Johannes Trithemius writes about da Correggio boasting of himself as knowing all the learnings of the ancient Hebrews, Greeks, and Latins.
He makes use a popular alchemical symbol, the phoenix (often associated with the philosopher's stone), which he says perches on the upper branches of the papal tree.
Da Correggio writes De Quercu as if he is the conduit of a divine entity, imploring the pope's help in the third person: "Give our Giovanni Mercurio your help and I will help you."
[21] The first modern authority to describe Giovanni da Correggio was Kurt Ohly while he was researching Lazzarelli's Epistola Enoch in 1938.
Paul Oskar Kristeller was the next authority to write about da Correggio while researching Hermetic documents and manuscripts in the Viterbo Municipal Library.
[2] Other sources found by Kristeller include the Harley Manuscript 4081 in the British Museum, better known as De Quercu,[23] as well as da Correggio's sonnet with Sosenna's commentary.