Barry Schwabsky at The Nation:
The art that flourished in Italy in that period has come to be known as Mannerism, and from the seventeenth through the nineteenth centuries it was considered of no intrinsic interest, merely (as one art historian summarized it) “a servile, uncritical imitation of the manners of the great masters, and especially of the anatomical exaggerations of Michelangelo’s figure style.” In the twentieth century, parallels with aspects of modernism—those expressive distortions of the figure that, as Matisse would have it, turned the image of a woman into a painting—breathed new life into an art that had lain neglected for centuries. To eyes liberated from the old canons of realism, the Mannerists could be seen not as weak imitators but as true originals whose disproportionate emotional and intellectual demands on their own art made them seem uncannily contemporary: the American kids on their Fulbrights are crazy for them, Roberto Longhi was to note, with some condescension, in the 1950s. And yet even then, and still today, it would have been hard to argue that the great Italian art of the sixteenth century was Florentine Mannerism—not when the likes of Titian, Tintoretto and Paolo Veronese were flourishing in Venice, which despite certain setbacks was largely insulated from the warfare and religious upheaval common elsewhere in Italy. The Venetians, and especially Tintoretto, may at times show mild affinities with their central Italian contemporaries, but they never betray the anxiety and inner conflict we find among the Mannerists.
more here.