The Caravaggisti were a group of Caravaggesque painters from the sixteenth and seventeenth centuries. They painted in or were influenced by Caravaggio’s brooding, dramatic, and realistic (unidealizing) style.
For more information about the Caravaggisti, I recommend the following books (although this of course is not an exhaustive list):
1. Richard Spear, Caravaggio and his Followers
2. David Franklin & Sebastian Schutze, Caravaggio and his Followers in Rome
3. Linda Freeman Bauer, Moral and Choice in Some Paintings by Caravaggio and his Followers (Art Bulletin, Sep. 1991)
4. Dennis Weller, Caravaggio and his Dutch & Flemish Followers
For some fun information, feel free to read about the falling out Caravaggio had with one of his stylistic followers in the summer of 1603.