An origin story which claimed Tacitus to be the heir of an old Umbrian family and one of the wealthiest men of the empire with a total wealth of 280 million sestertii circulated after his coronation.

According to the Historia Augusta, Tacitus, after ascertaining the sincerity of the Senate's regard for him, accepted their nomination on 25 September 275,[7] and the choice was cordially ratified by the army.

[10] In older historiography, it was generally accepted that Aurelian's wife, Ulpia Severina, ruled in her own right before the election of Tacitus which could indicate an interregnum which lasted as long as six months.

He granted substantial prerogatives to the Senate, securing to them by law the appointment of the emperor, of the consuls, and the provincial governors, as well as supreme right of appeal from every court in the empire in its judicial function, and the direction of certain branches of the revenue in its long-abeyant administrative capacity.

[13] 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 around June 276, after a rule of just over 6 months.