Trajan was notable for fighting two wars, one against the Dacians and the other against the Parthians. Decebalus ruled the Dacian kingdom and he had become a threat to the Roman empire. Trajan was determined to put an end to Decebalus' reign. During the first Dacian War (101-102 AD), Trajan defeated the Dacians in heavy fighting, and Decebalus came to terms with Trajan. Trajan than embarked on a second conquest in order to take over the enitre kingdom, which became the Roman province of Dacia.
In 114 AD, Trajan defeated the Parthians and conquered the mountain kingdom of Mesopotamia and advanced far as the Persian Gulf. However these conquests could be held, Trajan had been forced to abandon southern Mesopotamia when he died in August 117 AD.