Lamps with workshop seal - firmalampen, are the first factory products made in large series since the mid-1st century in the workshop centres of northern Italy, southern France and the Rhineland, from where they reached all parts of the Roman Empire. Since transport was expensive, and lamps were very popular, local workshops were opened with the establishment of the Roman administration, where imitation of lamps from well-known manufacturers were produced. One such workshop, perhaps as early as the mid-2nd century, also existed in Singidunum. There are over 200 lamps of this type in the collection of the Belgrade City Museum. Judging by the number, the most popular lamps in Singidunum were by the manufacturer FORTIS, who is considered the father of this form. In addition to these lamps, there are also products from the workshops of Agilis, Cassi, Festi, Fronto, Neri, Sexti, Octavi, but also lamps from local masters Flavi and Ianvari.