Created in AD 106 by the Roman emperor Trajan after the final defeat of Decebalus' Dacian kingdom, it was originally a single province under the name Dacia, governed by a Legatus Augusti pro praetore.
During all these transformations, Dacia Superior/Dacia Apulensis was governed by a consular legate, while the other two provinces were under the command of praesidial procurators.
Then in 166, the pressures building along the Danube frontier forced the new emperor Marcus Aurelius to reorganise the province once again.
However, the three provinces still remained as separate entities, each one governed by a praesidial procurator, who then reported to the proconsular governor.
Apart from a brief period during the Marcomannic Wars when the province was temporarily split into three due to an emergency situation, Tres Daciae retained this structure until Aurelian abandoned the province in 271.