Founded at an as-yet-unspecified date, but probably before the 5th century BC, Bulla Regia (Latin for "Royal Bulla”) seems to have undergone rapid growth and prosperity. After 46 BC, the city began to gradually become Roman. The Greek-Roman religion, the new Roman names born by its inhabitants, and the use of the Latin language began to spread in everyday life. The city experienced different municipal statuses at the same time as it acquired monumental finery. All the essential elements of a city are represented in Bulla such as a forum, civil basilicas, public baths (Memmian baths, great southern baths, north-western theatre baths...), a library, a market, a theatre, an amphitheater, a capitol (dedicated to Jupiter, Juno, and Minerva), temples of Apollo, Isis, Saturn...
Bulla Regia owes its fame to its prestigious houses with subterranean floors, real jewels of domestic architecture in ancient Tunisia. They were given various names such as Venus House, the Hunt House, the New Hunt house, the Fishing house, the Mosaics House, the Treasure-house... recalling the main discovery in these dwellings, often the theme of the mosaic floor.
Far too little is known about the period during which Africa fell under the domination of the Vandals (439-533). During the following period, when Africa depended on Byzantium (533-698), Bulla still retained certain importance. The military operations were undertaken during the Vandal and Byzantine periods do not seem to have had any real impact on city life. During these two periods, churches and a fort were built. Recent excavations have uncovered a new peripheral church and a vast Christian cemetery.
The gradual desertion of the town was probably only completed towards the end of the 12th century. The town did indeed decline, but the process was slow and the decline did not take a brutal form.