Legatio Ad Gaium

And when he could not persuade him, by all the arguments drawn from probabilities which he advanced, he brought forward that which rested upon specific agreements, adding, "I myself will be his security, I who deserve to have confidence placed in me, inasmuch as I have given sufficient proof that I myself am individually a friend to Caesar, and a friend to Tiberius, since it was I who carried into execution, your intentions respecting the downfall of Sejanus.