Short answers, pulled from the story.
Mannerism emerged in the later years of the Italian High Renaissance around 1520, spreading by about 1530 and lasting until about the end of the 16th century in Italy, when the Baroque style largely replaced it. Northern Mannerism continued into the early 17th century.
Mannerist art is characterized by elongated figures, distorted perspective, asymmetrical compositions, theatrical lighting, flat black backgrounds, atmospheric sfumato effects, serpentine movement, and intense pure colors such as blues, pinks, and yellows. It privileges compositional tension and instability over the balance and clarity of the High Renaissance.
Key Mannerist artists include Jacopo da Pontormo, Rosso Fiorentino, Agnolo Bronzino, Giorgio Vasari, El Greco, Benvenuto Cellini, Giambologna, Giuseppe Arcimboldo, and Lavinia Fontana. Lavinia Fontana (1552-1614) has been acknowledged as the first female career artist in Western Europe and was appointed Portraitist in Ordinary at the Vatican.
Mannerism spread through two main routes: Italian artists fled Rome after the Sack of Rome in 1527 and disseminated their style across Europe as they sought employment, while prints, engravings, and illustrated books carried Mannerist imagery to regions without direct contact with Italian artists. Rosso Fiorentino brought Florentine Mannerism to Fontainebleau in 1530, founding the School of Fontainebleau, and the style reached as far as Valletta, Malta, where architect Girolamo Cassar designed numerous buildings from the late 1560s onward.
Mannerism derives from the Italian word maniera, meaning style or manner. Giorgio Vasari used the term in the second edition of his Lives of the Most Excellent Painters, Sculptors, and Architects (1568) in several contexts, including to describe personal or group style and to affirm positive artistic quality. Vasari called the period in which he worked "la maniera moderna," meaning the modern style.
Neo-Mannerism in the 20th century emerged primarily through the work of artist Ernie Barnes, whose style featured subjects with elongated limbs, exaggerated movement, and closed eyes as a symbol of human blindness to one another's humanity. His exhibition "The Beauty of the Ghetto" toured major American cities between 1972 and 1979, and when it appeared at the Museum of African Art in Washington, D.C., in 1974, Representative John Conyers entered a statement about its message into the Congressional Record.