In the early Summer of 128, the Roman emperor Hadrian visited Lambaesis, the base of the Third Augustan Legion. As it happens, a substantial part of the speeches he delivered, survive. Much of it consists of topical praise, but the text is nevertheless interesting, because we can recognize that Roman legions were as hierarchically organized as Roman society in general.
My article on the subject was published in originally published as “Hadrian and his Soldiers. The Lambaesis Inscription“, in: Core of the Legions. The Roman Imperial Centuria = Ancient Warfare Special 2010. Because the publisher is a friendly person, it is now available online: here.