Palmyrene Empire
State · 261–269 CE · at its largest around 263 CE
Breakaway state led by Queen Zenobia of Palmyra, who seized Egypt and much of the Roman East before Aurelian defeated her.
On its lands while it lasted
- Tigranocerta (c. 326 BCE – c. 428 CE): Capital of Kingdom of Armenia (326 BCE–428).
- Edessa (302 BCE – 1150 CE): Capital of Kingdom of Osroene (63 BCE–214), County of Edessa (1099–1150).
- Palmyra (c. 261–1929 CE): Capital of Palmyrene Empire (261–269).
More on Wikipedia.