Whilst travelling through the provinces, Hadrian built everywhere great works. In Britain he erected the wall against the Caledonians for the protection of the province, which now already began to be Romanized, though indeed the Gaelic and Cymric elements of the population were likewise preserved. But above all, it was on Athens, which he enthusiastically loved, as well as on Greece in general, that he showered his benefits. He adorned Athens with works, the like of which had not been wrought for the city since the times of Pericles; he finished the Olympiëum, built a theatre and an entire new town, and even had himself invested with the dignity of an _Archon Eponymus_. In the last years of his life, he fell into a state of melancholy; and then, on the one hand, he sought for aid to secure the succession of the empire, and on the other, he gave way to sudden outbursts of anger and to mistrust, and was thus led to put many persons to death. He was an enemy to the Roman senate, which, however, in all likelihood was a set of presumptuous, overbearing, disagreeable people, who besides were enormously rich: it had now already come to pass, that in these wealthy families the senatorial dignity was handed down as an inheritance from father to son. Then it was that Hadrian first adopted a young man named Ælius Verus, in whom, however, he was unaccountably mistaken. On this occasion an immense _congiarium_ was given to the people. Most happily for Rome, this unworthy fellow died a short time afterwards; on which Hadrian chose T. Antoninus (Pius), whom he had already thought of before, a grandson of Arrius Antoninus, the friend of Nerva, and an altogether blameless man. Among the remarkable features of Hadrian’s reign, is the foundation of the system of Roman jurisprudence in its later form, the drawing up of the _edictum perpetuum_, and the further development of the law by means of imperial edicts. It is a new epoch in Roman jurisprudence; the _responsa prudentum_, now that they were given in the name of the emperor, acquired a real authority. The emperors had even since Augustus had a sort of council of state; but Hadrian put the _consistorium Principis_ on a surer footing: a regularly settled form that body never had. The _præfectus prætorio_ henceforth is a lawyer and not a military man, a strange combination in the manner of the East.