Despite the Empire's successes, the extensive military campaigns began to take their toll on Rome's finances. When Dacian tribes ravaged Roman lands, the unpopular Emperor Domitian was forced to raise taxes. He had never been on the front lines himself, but one of his generals, a young man named Trajan, soon proved to be a worthy leader while battling Germanic tribes on the Rhine.

After Domitian's murder, Trajan was proclaimed emperor and set out to rebuild the troubled Empire. He solved its financial problems by attacking the Dacian chieftain, Decebalus, uncovering his golden treasures that were hidden in a river.

In 106AD, Decebalus fled but Trajan's men hunted him down, only to find that he had killed himself to avoid the humiliation of defeat. Trajan's victory was immortalised in Trajan's Column in Rome and under his reign, the Empire reached its maximum extent of power.