A Double Victory?
Contributed by David Verne
The Sarmatians, an Iranian people that had migrated to Germany, have taken the opportunity presented by Saturninus' revolt to raid Moesia. Domitian tried to catch them, but they withdrew across the Danube before the Romans arrived. Still confident from Julianus' success against the Dacians last year, Domitian decides to invade two Germanic tribes, the Quadi and the Marcomanni, accusing them of not doing enough to help the Romans. The Marcomanni push back Domitian's army and raid the Roman province, Pannonia, before returning home.
Seeing a chance to negotiate, Decebalus, who has been preparing for a desperate defense of his capital, sends an envoy to Domitian to discuss peace terms. After being pushed out of Marcomanni lands, Domitian agrees to a peace treaty recognizing Dacia as a client kingdom of Rome. However, this treaty was controversial because Domitian agreed to pay a large annual tribute and sent engineers and military advisers to Decebalus. Domitian celebrated a double Triumph in Rome for his "victories" against Dacia and the Marcomanni. The Senate was shocked, and the officer corps considered the peace treaty borderline dereliction of duty. The treaty gave Rome peace, but it turned Roman taxes into Dacian swords and had Romans build walls that future Romans will die attacking. Decebalus' court will become a haven for Roman deserters and barbarian enemies of Rome. 
- Dando-Collins, Stephen (2010). Legions of Rome. St. Martin's Press.