[1837] Tac. Ann. iii. 14, xvi. 8; Suet. Aug. 5.
[1838] There was no legal principle of the kind. According to Dio Cassius (liii. 17) the monarchical power extended so far ὥστε καὶ ἐντὸς τοῦ πωμηρίου καὶ τοὺς ἰππέας καὶ τοὺς βουλευτὰς θανατοῦ δύνασθαι, and a senator, like Calpurnius Piso in 20 A.D., might be brought before the Emperor (Tac. Ann. iii. 10). But Septimius Severus permitted a senatus consultum to be passed that the Emperor should not be allowed to put a senator to death without the will of the Senate (Dio Cass. lxxiv. 2; Vita Severi 7). The principle had been stated earlier by Hadrian (Vita Hadriani 7 “juravit se nunquam senatorem nisi ex senatus sententia puniturum”).
[1839] Augustus in 29 B.C. brought Antiochus of Commagene, Tiberius in A.D. 17 Archelaus of Cappadocia before the Senate (Dio Cass. lii. 43, lvii. 17; Tac. Ann. ii. 42). In A.D. 19 Rhescuporis of Thrace was accused there (Tac. Ann. ii. 67).
[1840] Cases of extortion are to be found in Tac. Ann. iii. 66, xii. 59; Hist. iv. 45. In A.D. 23 we find the imperial procurator (patrimonii) of Asia brought before the Senate for exceeding his powers (Tac. Ann. iv. 15).
[1841] Tac. Ann. iv. 13 (A.D. 23) “Carsidius Sacerdos, reus tamquam frumento hostem Tacfarinatem juvisset, absolvitur, ejusdemque criminis C. Gracchus.”
[1842] Amongst the prosecutions for treason against the Princeps which disfigure the reign of Tiberius we may mention those against Libo Drusus (Tac. Ann. ii. 27 ff.), against Cremutius Cordus (ib. iv. 34, 35), and against Sejanus (Dio Cass. lviii. 9, 10).
[1843] In A.D. 37 we find that a mother, who had caused her son to commit suicide, “accusata in senatu ... urbe ... in decem annos prohibita est” (Tac. Ann. vi. 49). In A.D. 61 we find interdiction from Italy pronounced against a man for a kind of praevaricatio, “quod reos, ne apud praefectum urbis arguerentur, ad praetorem detulisset” (ib. xiv. 41).
[1844] Quintil. Inst. Or. iii. 10, 1; vii. 2, 20. For instances see Tac. Ann. ii. 50, iv. 21; Plin. Ep. ii. 11, 3 ff. In the last passage we find the question of the legality of this procedure raised (“Respondit Fronto Catius deprecatusque est ne quid ultra repetundarum legem quaereretur.... Magna contentio, magni utrimque clamores, aliis cognitionem senatus lege conclusam, aliis liberam solutamque dicentibus”).
[1845] It is possible, however, that the Senate was held to continue the extraordinary criminal jurisdiction of the comitia. Tacitus certainly regards the cognitio as belonging to the Senate (Ann. ii. 28 “Statim corripit reum, adit consules, cognitionem senatus poscit”).
[1846] Plin. Ep. vi. 31, 8 (in a case of a forgery of a will) “Heredes, cum Caesar (Trajanus) esset in Dacia, communiter epistula scripta, petierant ut susciperet cognitionem.”