Decebalus (r. AD 87-106) was Rome’s great Dacian enemy. He was also Romania’s great hero who fought the Roman Emperors Domitian and Trajan until his defeat and suicide in AD 106.
The king’s sculpture is the tallest rock relief in Europe, measuring 55 m (180 ft) in height and 25 m (82 ft) in width.
Here’s a good video on the Dacian conflicts:
Decebalus - The Brave One' - Last Mighty King Of Dacian People - Ancient Pages