The Square of the Corporations is one of the most famous monuments in Ostia. Many mosaic inscriptions and depictions are related to maritime trade, to importing goods for Rome by ship: grain, olive oil, wild animals, and so on. The city of Rome was a major focus of the Mediterranean trade, involving especially the western Mediterranean sea.

The square is situated behind the theatre, from which it is separated by a long row of marble columns. Around the remaining three sides runs a double porticus, containing many small rooms. The rooms were in antiquity called stationes: stations or offices. In the front and sometimes in the back rooms the many black-and-white mosaics can be seen from a modern path next to them. The mosaic inscriptions mention skippers (navicularii) and traders (negotiantes) who were united in guilds (collegia). Many depictions can be seen of dolphins, ships and the lighthouse at Portus. Grain measures (pecks) refer to the most important commodity for the population of Rome. In the centre of the square was a temple, perhaps dedicated to the Imperial Annona, the personification of the food supply. Most mosaics were installed in the late second century. In this period the theatre was rebuilt by Commodus and inaugurated by his successors Septimius Severus and his son Caracalla, in 196 AD.

In the section Topics you can find a summary of the square and an extensive description of the square.

The archaeologist Guy de la Bédoyère made a movie of a walk along the offices. A movie in Italian, presented by Sergio Rinaldi Tufi, is provided by the Parco Archeologico di Ostia Antica.

The square seen from the theatre.
Photo: Klaus Heese.