The floors of many churches in Rome are embellished with a distinctive type of inlaid stone decoration, which is known as Cosmati work, or Cosmatesque.
The Cosmati were a Roman dynasty of marble workers, who were active over four generations in the 12th and 13th centuries. They created ornate geometric designs, mostly for church floors, making extensive use of porphyry and verde antico, recycled from the surviving buildings of ancient Rome, which they sliced and diced into circles, squares, triangles and lozenges. Employing the technique of opus sectile (cut work), they set the shapes in a framework of white Carrara marble to create a pattern of roundels and rectangular panels linked together to produce the characteristic chain effect.
The Cosmati were predominantly active in Rome and the surrounding region of Lazio.