or, with his full name, TIB. CLAUDIUS DRUSUS NERO GERMANICUS, was the fourth in the series of Roman emperors, and reigned from A. D. 41 to 54. He was the grandson of Tib. Claudius Nero and Livia, who afterwards married Augustus, and the son of Drusus and Antonia. He was born on the first of August, B. C. 10, at Lyons in Gaul, and lost his father in his infancy. During his early life he was of a sickly constitution, which, though it improved in later years, was in all probability the cause of the weakness of his intellect, for, throughout his life, he shewed an extraordinary deficiency in judgment, tact, and presence of mind. It was owing to these circumstances that from his childhood he was neglected, despised, and intimidated by his nearest relatives; he was left to the care of his paedagogues, who often treated him with improper harshness. His own mother is reported to have called him a portentum hominis, and to have said, that there was something wanting in his nature to make him a man in the proper sense of the word. This judgment, harsh as it may appear in the mouth of his mother, is not exaggerated, for in everything he did, and however good his intentions were, he failed from the want of judgment and a proper tact, and made himself ridiculous in the eyes of others. Notwithstanding this intellectual deficiency, however, he was a man of great industry and diligence. He was excluded from the society of his family, and confined to slaves and women, whom he was led to make his friends and confidants by his natural desire of unfolding his heart. During the long period previous to his accession, as well as afterwards, he devoted the greater part of his time to literary pursuits, Augustus and his uncle Tiberius always treated him with contempt; Caligula, his nephew, raised him to the consulship indeed, but did not allow him to take any part in public affairs, and behaved towards him in the same way as his predecessors had done.

In this manner the ill-fated man had reached the age of fifty, when after the murder of Caligula he was suddenly and unexpectedly raised to the imperial throne. When he received the news of Caligula's murder, he was alarmed about his own safety, and concealed himself in a corner of the palace; but he was discovered by a common soldier, and when Claudius fell prostrate before him, the soldier saluted him emperor. Other soldiers soon assembled, and Claudius in a state of agony, as if he were led to execution, was carried in a lectica into the praetorian camp. There the soldiers proclaimed him emperor, and took their oath of allegiance to him, on condition of his giving each soldier, or at least each of the praetorian guards, a donative of fifteen sestertia--the first instance of a Roman emperor being obliged to make such a promise on his accession. It is not quite certain what may have induced the soldiers to proclaim a man who had till then lived in obscurity, and had taken no part in the administration of the empire. It is said that they chose him merely on account of his connexion with the imperial family, but it is highly probable that there were also other causes at work.

During the first two days after the murder of Caligula, the senators and the city cohorts, which formed a kind of opposition to the praetorian guards, indulged in the vain hope of restoring the republic, but being unable to make lead against the praetorians, and not being well agreed among themselves, the senators were at last obliged to give way, and on the third day they recognized Claudius as emperor. The first act of his government was to proclaim an amnesty respecting the attempt to restore the republic, and a few only of the murderers of Caligula were put to death, partly for the purpose of establishing an example, and partly because it was known that some of the conspirators had intended to murder Claudius likewise. The acts which followed these shew the same kind and amiable disposition, and must convince every one, that, if he had been left alone, or had been assisted by a sincere friend and adviser, his government would have afforded little or no ground for complaint. Had he been allowed to remain in a private station, he would certainly have been a kind, good, and honest man. But he was throughout his life placed in the most unfortunate circumstances. The perpetual fear in which he had passed his earlier days, was now increased and abused by those by whom he was surrounded after his accession. And this fear now became the cause of a series of cruel actions and of bloodshed, for which he is stamped in history with the name of a tyrant, which he does not deserve.

The first wife of Claudius was Plautia Urgulanilla, by whom he had a son, Drusus, and a daughter, Claudia. But as he had reason for believing that his own life was threatened by her, he divorced her, and married Aelia Petina, whom he likewise divorced on account of some misunderstanding. At the time of his accession he was married to his third wife, the notorious Valeria Messalina, who, together with the freedmen Narcissus, Pallas, and others, led him into a number of cruel acts. After the fall of Messalina by her own conduct and the intrigues of Narcissus, Claudius was, if possible, still more unfortunate in choosing for his wife his niece Agrippina, A. D. 49. She prevailed upon him to set aside his own son, Britannicus, and to adopt her son, Nero, in order that the succession might be secured to the latter. Claudius soon after regretted this step, and the consequence was, that he was poisoned by Agrippina in A. D. 54.

The conduct of Claudius during his government, in so far as it was not under the influence of his wives and freedmen, was mild and popular, and he made several useful and beneficial legislative enactments. He was particularly fond of building, and several architectural plans which had been formed, but thought impracticable by his predecessors, were carried out by him. He built, for example, the famous Claudian aquaeduct (Aqua Claudia), the port of Ostia, and the emissary by which the water of lake Fucinus was carried into the river Liris. During his reign several wars were carried on in Britain, Germany, Syria, and Mauretania; but they were conducted by his generals. The southern part of Britain was constituted a Roman province in the reign of Claudius, who himself went to Britain in A. D. 43, to take part in the war; but not being of a warlike disposition, he quitted the island after a stay of a few days, and returned to Rome, where he celebrated a splendid triumph. Mauretania was made a Roman province in A. D. 42 by the legate Cn. Hosidius.