The Kingdom of Dacia , under King Decebalus , had become a threat to the Roman Empire .
The Kingdom of Dacia , under King Decebalus , defeated several of Rome 's armies during Domitian 's reign ( 81 - 96 ) .
The Kingdom of Dacia , under King Decebalus , had become a threat to the Roman Empire , and defeated several of Rome 's armies during Domitian 's reign ( 81 - 96 ) .