What is known as the Neapolitan School of Painters originated with Michelangelo Amerigi, called Caravaggio after his birthplace near Milan where he first saw the light in 1569. Undaunted by the great achievements of the Italian masters who immediately preceded him, Caravaggio sought to form an independent style of his own, instead of slavishly copying Titian, Tintoretto, Raphael and Michel Angelo. As Sir William Orpen points out, Caravaggio saw the error of his contemporaries and "perceiving that art based on art leads to decadence, he gave his whole attention to nature and so became a pioneer of realism." His real fight, observes Professor Mather, "was with the nobility of Raphael. His saints are taken from the streets and often from the gutters. He loves character above all, and wants it proletarian. Within his chosen limitations he admittedly is a powerful and sincere artist."

Both at Rome and Naples this sturdy, swaggering Caravaggio appears to have had an immense success. His pictures – especially portraits – are said to have commanded better prices than were obtained by any of his contemporaries. He boasted himself the greatest painter of all time, and was often believed. From his swarthy tones his school of disciples took the name of Tenebrists. The novelty in his treatment chiefly consisted of the use Caravaggio made of light and shade, technically known as chiaroscuro to render his pictures more dramatically intense. He exaggerated his shadows which, to quote Orpen, "were far too black to be scrupulously faithful to nature, but by the emphasis he thus gave to his lights he produced original and arresting effects which undoubtedly had a powerful influence on the two greatest painters of the next generation – Velasquez and Rembrandt."

In his own time, Caravaggio's experiments in interior and artificial lighting were widely imitated, and again are to be seen in modern impressionistic painting. His rejection of noble form – of the idealistic method – in favor of what one sees with the naked eye, and of decorative color in favor of natural, was a sharp and direct challenge of the Renaissance style, and outside of Italy where the noble tradition was only incipient, Caravaggio did much to arrest its influence. Mather goes on to say, "From the point of view of modern art there are few more important figures than that of Caravaggio. From the point of view of art broadly he has his serious limitations. Most damaging is his waiver of civilization, he looks at low life not with the eyes of a detached artist but with those of a ruffian.