Capital: Sarmizegetusa Regia
Official Languages: Dacian
Established: 168 BC/BCE
Disestablished: 106 AD/CE
The Dacia of King Burebista (82–44 BC/BCE), stretched from the Black Sea to the source of the river Tisa and from the Balkan Mountains to Bohemia. During that period, the Geto-Dacians conquered a wider territory and Dacia extended from the Middle Danube to the Black Sea littoral (between Apollonia and Olbia) and from present-day Slovakia's mountains to the Balkan mountains. In 53 BC, Julius Caesar stated that the lands of the Dacians started on the eastern edge of the Hercynian Forest (Black Forest). After Burebista's death, his kingdom split in four states, later five.
Ptolemy also provided a couple of Dacian toponyms in south Poland in the Upper Vistula (Polish: Wisla) river basin: Susudava and Setidava (with a manuscript variant Getidava). This could have been an "echo" of Burebista's expansion. It seems that this northern expansion of the Dacian language, as far as the Vistula river, lasted until AD/CE 170–180 when the migration of the Vandal Hasdingi pushed out this northern Dacian group. This Dacian group, possibly the Costoboci/Lipiţa culture, is associated by Gudmund Schütte with towns having the specific Dacian language ending "dava" i.e. Setidava.
The Roman province Dacia Traiana, established by the victors of the Dacian Wars during AD/CE 101–106, initially comprised only the regions known today as Banat, Oltenia, Transylvania, and was subsequently gradually extended to southern parts of Moldavia, while Dobruja and Budjak belonged the Roman province of Moesia.
In the 2nd century AD, after the Roman conquest, Ptolemy puts the eastern boundary of Dacia Traiana (the Roman province) as far east as the Hierasus (Siret) river, in the middle of modern Romania. Roman rule extended to the south-western area of the Dacian Kingdom (but not to what later became known as Maramureş), to parts of the later Principality of Moldavia east of the Siret and north of the Upper Trajan Wall, and to areas in modern Muntenia and Ukraine, except the Black Sea shore.
After the Marcomannic Wars (AD/CE 166–180), Dacian groups from outside Roman Dacia had been set in motion. So were the 12,000 Dacians 'from the neighbourhood of Roman Dacia sent away from their own country'. Their native country could have been the Upper Tisa region, but other places cannot be excluded.
The later Roman province Dacia Aureliana, was organized inside former Moesia Superior after the retreat of the Roman army from Dacia, during the reign of emperor Aurelian during AD/CE 271–275. It was reorganized as Dacia Ripensis (as a military province) and Dacia Mediterranea (as a civil province).