Our own Morgan Meis in The Smart Set:
“Mannerism” sounds stupid. One immediately associates it with manners. And “manners” are not in the highest regard these days. Mannerism would seem to be a movement of affected and empty gestures, of style over substance.
That's what many do mean when they use the term. Mannerism has come to refer, primarily, to the group of Italian artists working just after the close of the High Renaissance. Leonardo da Vinci died in May 1519; you could say, then, that Mannerism started in early June of that same year. The Mannerists, left with nowhere to go by the transcendent greatness of the High Renaissance artists, had no choice but to become decadent and unhinged.
Mannerist artists like Jacopo da Pontormo thus wasted little time in screwing up the Renaissance. Pontormo painted his figures in crazy contorted poses that would have made Leonardo revisit his lunch. Pontormo also went nuts with color. Many of the scenes he painted have an otherworldly luminosity that is hard to describe. You almost want to call it DayGlo. His compositions veer toward the “jumbly.” What, exactly, is happening in “Joseph in Egypt”? The staircase to nowhere dominates the canvas and it looks like Pontormo simply forgot to finish the landscape in the background. A cherub vamps atop a random column stuck on the far right side of the scene. This, gentlemen, is not Michelangelo.
It is for all these reasons and more that I have come to love Mannerism.
More here.