What happened 276 AD

On his way back to the west to deal with a Frankish and Alamannic invasion of Gaul, according to Aurelius Victor, Eutropius, and the Historia Augusta, Tacitus died of fever at Tyana in Cappadocia in June 276.

After Tacitus died suddenly in July 276, allegedly as a consequence of a military plot, Florian swiftly proclaimed himself emperor and was recognized as such by the Roman Senate, and the western provinces.

Florian led his troops to Cilicia and billeted his forces in Tarsus. However many of his troops, who were unaccustomed to the hot climate of the area, fell ill due to a summer heatwave. Upon learning of this, Probus launched raids around the city, in order to weaken the morale of Florian's forces. This strategy was successful, and Florian lost control of his army, which in September rose up against him and killed him. In total, Florian's reign lasted less than three months.

Florian, the half-brother of Tacitus, also proclaimed himself emperor, and took control of Tacitus' army in Asia Minor, but was killed by his own soldiers after an indecisive campaign against Probus in the mountains of Cilicia. In contrast to Florian, who ignored the wishes of the senate, Probus referred his claim to Rome in a respectful dispatch. The senate enthusiastically ratified his pretensions.

Pyrrhus received a head wound but managed to overcome the Mamertines. He arrived in Tarentum in the autumn of 276 BC with 20,000 men.