The lands of the Dacia people were southeast of the Danube, to the east of Gaul and Italy, west of the Black Sea. They were rivals of Rome from 168 BCE until Emperor Trajan defeated them in 106 CE. Their territories included some land in modern Hungary, Romania, Moldova, Bulgaria, Ukraine, and Serbia. Decebalus, the last King of the Dacians, at least in legend invited Jews who helped him in wars against Rome to live freely in his kingdom. Decebalus is still a hero figure to many Romanians, the ethnic descendants of Dacians.
It’s unknown exactly how early Jews arrived in Dacia but they were certainly present by the 3rd century, according to archeological finds. A headstone for a Jewish woman in Latin identifies her as Septima Maria, a “Judaea”. An official tablet was signed by the “archisynagogus” or head of the synagogue, during the 208-235 CE reign of Alexander Severus. An amulet shaped like a gold scroll, enscribed with a Jewish prayer and dated to the third century, was found in Austria, neighbor to Hungary.
Rome may have conquered Dacia, but Celtic and Germanic tribes from the north approached. In 275 CE, Goths ousted the Romans and left Dacia to the Carpi – free Dacians. For a period Rome tried to fight for it back, but Goths were invading via Thrace by then, and Rome had to pick their battles, literally. It wasn’t until Emperor Constantine that the great empire would try in earnest. In 332, Constantine convinced Samaritans to ally with him against Goths, to victory. But in 334 when Samaritan commoners overthrew their local government he had some deported to Illyrian farmlands and the rest conscripted to his army.
In 376 CE, Roman Dacia was overtaken by Atilla the Hun until his death in 453. The Hun were a Central Asian steppes people, possibly from the Chinese Han dynasty. Then the Gepids, an eastern Germanic tribe of cousins to the Goths, settled in until 566. That’s when the Lombards, also German, came down from the north and removed them. The Avars and their client tribe the Bulgars then moved west out of the Göktürk Empire. They offered to become a client mercenary state of Byzantine, subjugating nomadic tribes in exchange for gold and fertile lands.
The Byzantines agreed and by 562 CE the Avars held the lands north of the Black Sea. The Avars negotiated with the Lombards: work together to take out the Gepids, Avar would take former Dacia, leaving southern Italian conquest to the Lombards. It was a deal, and it worked. By 580 the Byzantines were behind on the bills so the Avar went to war, making merry sport of the Baltics. They joined the Persian side in the Siege of Constantinople, but when it failed the Avars lost some world standing. By the end of the 7th century they’d experienced a lot of Slavic and a little East Asian immigration.