Alba Iulia (German: Karlsburg, Hungarian: Gyulafehérvár) is a city in Alba county, Transylvania, Romania with a population of 66,369.
The city was inhabited by the Dacians (named "Apoulon"), then to be conquered by the Romans and renamed "Apulum". Renamed once again in the Middle ages as "Balgrad" ("the white city") or "Gyulafehérvár" (by the Hungarians), it became the capital of the Transylvanian principality and an important cultural center.
In November 1599, Mihai Viteazul entered Alba Iulia and became the prince of Transylvania, then in 1600 to unify all three Romanian principalities, but only for a year. It was only on December 1, 1918 that Romanian states were reunified by a popular plebiscite held in Alba Iulia.