Early theorists

Giorgio Vasari
Giorgio Vasari's opinions about the "art" of creating art come through in his praise of fellow artists in the great book that lay behind this frontispiece: he believed that excellence in painting demanded refinement, richness of invention (invenzione), expressed through virtuoso technique (maniera), and wit and study that appeared in the finished work, all criteria that emphasized the artist's intellect and the patron's sensibility. The artist was now no longer just a craftsman member of a local Guild of St Luke. Now he took his place at court with scholars, poets, and humanists, in a climate that fostered an appreciation for elegance and complexity. The coat-of-arms of Vasari's Medici patrons appear at the top of his portrait, quite as if they were the artist's own.
The framing of the engraved frontispiece to Mannerist artist Giorgio Vasari's Lives of the Artists would be called "Jacobean" in an English-speaking context. In it, Michelangelo's Medici tombs inspire the anti-architectural "architectural" features at the top, the papery pierced frame, the satyr nudes at the base. In the vignette of Florence at the base, papery or vellum-like material is cut and stretched and scrolled into a cartouche (cartoccia). The design is self-conscious, overcharged with rich, artificially "natural" detail in physically improbable juxtapositions of jarring scale changes, overwhelming as a mere frame: Mannerist.
Gian Paolo Lomazzo
Another literary source from the period is Gian Paolo Lomazzo, who produced two works—one practical and one metaphysical—that helped define the Mannerist artist's self-conscious relation to his art. His Trattato dell'arte della pittura, scoltura et architettura (Milan, 1584) is in part a guide to contemporary concepts of decorum, which the Renaissance inherited in part from Antiquity but Mannerism elaborated upon. Lomazzo's systematic codification of aesthetics, which typifies the more formalized and academic approaches typical of the later 16th century, controlled a consonance between the functions of interiors and the kinds of painted and sculpted decors that would be suitable. Iconography, often convoluted and abstruse, is a more prominent element in the Mannerist styles. His less practical and more metaphysical Idea del tempio della pittura ("The ideal temple of painting", Milan, 1590) offers a description along the lines of the "four temperaments" theory of the human nature and personality, containing the ex

Early mannerism

Depending on the historical account, Mannerism developed between 1510 and 1520 in either Florence,Rome, or both cities. The early Mannerists in Florence—especially the students of Andrea del Sarto: Jacopo da Pontormo and Rosso Fiorentino—are notable for elongated forms, precariously balanced poses, a collapsed perspective, irrational settings, and theatrical lighting. Parmigianino, a student of Correggio, and Giulio Romano, Raphael’s head assistant were moving in similarly stylized aesthetic directions in Rome. These artists had matured under the influence of the High Renaissance, and their style has been characterized as a reaction or exaggerated extension of it. Instead of studying nature directly, younger artists began studying Hellenistic sculptures and paintings of masters past. Therefore, this style is often identified as "anti-classical”.yet at the time it was considered a natural progression from the High Renaissance. The earliest experimental phase of Mannerism, known for its "anti-classical" forms, lasted until about 1540 or 1550. Marcia Hall notes in her book 'After Raphael' Raphael's premature death marked the beginning of Mannerism in Rome.
Michelangelo was one of the great creative exponents of Mannerism and it was his style which raised the standard of art to a new level. His varied Ignudi painted in distinctive positions on the Sistine Chapel ceiling could have been influenced by the "Belvedere Torso” and which influenced other painters.
Raphael’s "Lo Spasimo di Sicilia” depicts an event in Christian history when Christ falls while carrying the cross, sees his mother in distress and is helped up by Simon of Cyrene. The composition is linked by the diagonals of the soldiers’ spears and the wooden cross. Unusually, Christ cannot be singled out immediately amongst the gathering figures in the foreground, whereas Simon stands out quite prominently. The spectator’s eyes look down the composition to the drama and charge of the narrative.
The competitive spirit which was spurred on by the patrons encouraged the artists to show off their virtuoso painting. When in Florence Leonardo and Michelangelo were each given a commission by Gonfaloniere Piero Soderini to decorate a wall in the “Hall of Five Hundred”. These two artists were set to paint side by side and compete against each other fueling the incentive of being as innovative as possible. Later on in Rome Raphael was commissioned to paint “The Transfiguration” by Cardinal Gioulio di Medici who had been appointed as arch bishop of Narbonne in the south of France. At this time Raphael was also busy painting the Stanze, various altarpieces, painting versions of Madonna and child and being the principal architect in Rome after the death of Bramante which gave him little time to do “The Transfiguration”. Therefore the cardinal commissioned Sebastiano del Piombo who was great Venetian colourist and a friend of Michelangelo to paint “The Raising of Lazarus”. This spurred Raphael on to complete the commission.
This period has been described as both a natural extension of the art of Andrea del Sarto, Michelangelo, and Raphael, as well as a decline of those same artists' classicizing achievements. In past analyses, it has been noted that mannerism arose in the early 1500s alongside a number of other social, scientific, religious and political movements such as the Copernican model, the Sack of Rome, and the Protestant Reformation's increasing challenge to the power of the Catholic church. Because of this, the style's elongated forms and distorted forms were once interpreted as a reaction to the idealized compositions prevalent in High Renaissance art. This explanation for the radical stylistic shift c. 1520 has fallen out of scholarly favor, though the early Mannerists are still set in stark contrast to High Renaissance conventions; the immediacy and balance achieved by Raphael's School of Athens, no longer seemed interesting to young artists. Indeed, Michelangelo himself displayed tendencies towards Mannerism, notably in his vestibule to the Laurentian Library, in the figures on his Medici tombs, and above all in his Last Judgment.