The last of our emperors in this segment is Probus, who ascended following the short reigns of Tacitus and Florianus. He first had to deal with an attack on Gaul by Franks, Vandals, and Burgundians in 277 A.D, which took two years to put down -- the most serious unrest in Gaul in 300 years. The remainder of his reign (three years) involved putting down insurrections among his own generals. In 283 A.D, they finally murdered him.
Here we reach an inflection point in the history of the empire. As the year 284 A.D. unfolded, a period of quiescence began which would last about eighty years. The driving forces behind this trend were two: strong leadership and a new model for managing the vast territory that was the Roman Empire.