Suetonius Tiberius 33

He assumed the sovereignty ¹ by slow degrees, and exercised it for a long time with great variety of conduct, though generally with a due regard to the public good. At first he only interposed to prevent ill management. Accordingly, he rescinded some decrees of the senate; and when the magistrates sat for the administration of justice, he frequently offered his service as assessor, either taking his place promiscuously amongst them, or seating himself in a corner of the tribunal. If a rumour prevailed, that any person under prosecution was likely to be acquitted by his interest, he would suddenly make his appearance, and from the floor of the court, or the praetor's bench, remind the judges of the laws, and of their oaths, and the nature of the charge brought before them. He likewise took upon himself the correction of public morals, where they tended to decay, either through neglect, or evil custom.