Tiberius II was adopted as heir by an emperor who had lost his mind, ruled four years, gave away the treasury in tax remissions and gifts, and chose Maurice to follow him.
Tiberius commanded the excubitors — the palace guard — when the emperor Justin II's mind gave way, and was adopted as Caesar in 574 in one of Justin's lucid intervals.
He governed in the emperor's name for four years and in his own from 578, and the four years of his sole reign are remembered mainly for spending.
He remitted a year's taxes, distributed largesse on a scale the sources dwell on, and emptied the reserves that Justin's parsimony had accumulated. He also made the one decision that mattered: he chose Maurice.
He was a Thracian, born about 535, and made his career in the guard rather than in the field armies — the same route Justin I had taken sixty years before.
He commanded against the Avars in the early 570s without much success, which did not prevent his promotion, and was close enough to the empress Sophia for the sources to speculate about her intentions towards him.
The adoption of 574 was arranged by Sophia and by Justin in a lucid interval, and the speech Justin is said to have made on the occasion — warning the new Caesar not to repeat his own mistakes — is among the most striking passages in John of Ephesus.
The tradition is warm about him in a way it is about very few emperors, and the warmth is specifically about generosity.
He is described as handsome, affable, merciful to opponents and incapable of refusing a request — remitting taxes, funding building, paying for games, and giving away treasure that the empire, fighting on three frontiers, urgently needed.
The empress Sophia, who had expected to govern through him, found he would not be governed and quarrelled with him. What the sources present as amiability, a treasury official would have called something harsher, and Maurice inherited the consequences.
The Persian war continued, and here his judgement was sound: he promoted Maurice, an official with no field experience, to command in the east, and Maurice won a significant victory at Solachon in 586 — after Tiberius's death, but with the army he had rebuilt.
In the Balkans the position deteriorated. Sirmium, the great fortress on the Save, fell to the Avars in 582 after a long blockade, and Slavic groups moved south in numbers that the empire could not answer.
In Italy the Lombards continued to advance, and Tiberius's response — subsidising the Franks to attack them — was the traditional expedient and did not work.
His reign is short and the record mixed, but the succession he arranged gave the empire twenty years of competent government under Maurice at a moment when it could have had none.
That is also the tragedy of it, because Maurice's murder in 602 by the mutiny that raised Phocas is the event that begins the seventh-century catastrophe. Tiberius chose well and the choice was undone by a payroll dispute on the Danube.
The treasury he emptied is the other half of his record, and it is not a small charge: the empire fought the wars of the next two decades without the reserve that Anastasius had built and Justin II had guarded.