Trebonianus Gallus (206-253) was a respected politician and general in the Roman Empire; and rose to power after the deaths of co-Emperors Trajan Decius and his son Herennius Etruscus during the Battle of Abrittus in 251. Some rumours claim that Gallus had had a hand in the deaths of Decius and his son; having conspired with the Goth invaders.

His soldiers proclaimed Gallus emperor; but Decius' other son Hostilian had been acknowledged by the people of Rome as rightful heir. Not wishing to start another civil war; Gallus acquiesced to the will of the Roman people and adopted Hostilian as his son; becoming co-emperors together. Hostilian's death to plague barely months into his rule in 251 allowed Gallus to rule alongside his son Volusianus as new co-emperors.

Like the reign of those before him; Gallus had to contend with revolts and foreign invasions. Aemilianus; governor of the provinces of Moesia Superior and Pannonia; took the initiative and defeated invaders threatening the eastern Roman frontier in 253. He was then proclaimed as emperor by his troops; and marched to Rome to fight for his claim; defeating Gallus and Volusianus in battle; who were subsequently killed by their own troops in August 253.