Micromosaics were hotly collected throughout the 18th and early 19th centuries. The finest examples were to be found in Italy, where several expert mosaicists had established workshops in Rome and Naples. They catered for a market of wealthy collectors, who journeyed through the Mediterranean on Grand Tours.The firm of Castellani, which was based in Rome and created this brooch, raised the medium to dazzling new levels of design in the later 19th century.