To better understand the evolution of this architectural ensemble, one must envision a series of overlapping layers of visible history that unfolded over time. First, there was the Roman presence in the form of a legionary castrum (XIII Gemina), of which some imprints still remain. Over this legionary castrum, a post-Roman layer was added, followed by a medieval layer, unfolding through multiple phases, one of the most visible today dating back to the late 13th century, after the Arpadian dynasty period of the Hungarian kings. It was during this time that the construction of a residence, used as a new episcopal seat, began. From the mid-16th century, the expansion of the ensemble started and continued until the 19th century, undergoing a Renaissance and Baroque period, along with the presence of the Habsburg garrison stationed here, which decisively influenced the current form of the ensemble.

The present configuration of this ensemble is incomplete. From the old complex, which reached its final form in the 17th century after significant contributions from Queen Isabella Jagiello and Princes Gabriel Bethlen and Gheorghe Rákóczi I, approximately 2/3 remains. The Habsburg administration’s decision to split this ensemble into two parts, west and east, based on the needs of the Habsburg army, led to this incompleteness.

After 1918, the building was taken over by the Romanian army, with the 91st Infantry Regiment of the Romanian Army being stationed here (the “King Ferdinand I” Barracks).

The Princes` Palace in Alba Iulia first caught the attention of archaeologists in 2014 when preliminary procedures for the restoration project of the building complex were initiated. The latest archaeological campaign took place in 2020 as part of the restoration project for the historical ensemble. It should be noted that the more significant parts of the former Princes` Palace of Transylvania, from the Principality period (1541-1711), were still located in the present headquarters of the Roman Catholic Archdiocese of Transylvania.