The twin towns of Apulum were a major urban centre of Roman Dacia, nowadays completely covered by the city of Alba Iulia.

Colonia Aurelia Apulensis was located south of the fortress on the bank of Marisus river and started as a pagus of Trajan's colony Ulpia Traiana Sarmizegetusa.

[7] Colonia Nova Apulensis developed closer to the fortress and was probably created by Septimius Severus (193-211) and initially named municipium Septimium Apulense.

The town was the site of the governor's palace in Dacia after the seat was moved from Sarmizegetusa around 158 under Antoninus Pius[9] and was one of the most extensive buildings of its type in the Roman Empire, complete with thermae, cult places, and staff offices and residences.

In the construction of the Early Medieval city of Gyulafehérvár, Roman stones were re-used for the first time as the unenduring provincial architecture collapsed naturally even before the Hungarian conquest.