The penultimate Julio-Claudian emperor, Claudius, is familiar to many of us through the BBC production of Robert Graves' I, Claudius series, starring Derek Jakobi as a stuttering Emperor Claudius. The real Ti. Claudius Nero Germanicus was born on August 1, in the year 10 B.C., in Gaul.

Family

Mark Antony may have lost to Octavian, later, the first emperor, Augustus, in the fight to inherit Julius Caesar's legacy, but Mark Antony's genetic line endured. Not directly descended from Augustus (of the Julian line), Claudius' father was Drusus Claudius Nero, a son of Augustus's wife Livia. Claudius' mother was Mark Antony's and Augustus' sister Octavia Minor's daughter, Antonia. His uncle was emperor Tiberius.

Slow Political Rise

Claudius suffered from various physical infirmities which many thought reflected his mental state, not Cassius Dio, though, who writes:

Book LX

In mental ability he was by no means inferior, as his faculties had been in constant training (in fact, he had actually written some historical treatises); but he was sickly in body, so that his head and hands shook slightly.

As a result, he was secluded, a fact that kept him safe. Having no public duties to perform, Claudius was free to pursue his interests and read and write, including material written in Etruscan. He first held public office at the age of 46 when his nephew Caligula became emperor in 37 A.D. and named him suffect consul.

How He Became Emperor

Claudius became emperor shortly after his nephew was assassinated by his bodyguard, on January 24, A.D. 41. The tradition is that the Praetorian Guard, located the aging scholar hiding behind a curtain, dragged him forth and made him emperor, although James Romm, in his 2014 exploration of the real Seneca, Dying Every Day: Seneca at the Court of Nero, says that it is likely that Claudius knew the plans in advance. Cassius Dio writes (also Book LX):

1 Claudius became emperor on this wise. After the murder of Gaius the consuls despatched guards to every part of the city and convened the senate on the Capitol, where many and diverse opinions were expressed; for some favoured a democracy, some a monarchy, and some were for choosing one man, and some another. 2 In consequence they spent the rest of the day and the whole night without accomplishing anything. Meanwhile some soldiers who had entered the palace for the purpose of plundering found Claudius hidden away in a dark corner somewhere. 3 He had been with Gaius when he came out of the theatre, and now, fearing the tumult, was crouching down out of the way. At first the soldiers, supposing that he was some one else or perhaps had something worth taking, dragged him forth; and then, on recognizing him, they hailed him emperor and conducted him to the camp. Afterwards they together with their comrades entrusted to him the supreme power, inasmuch as he was of the imperial family and was regarded as suitable.

3a In vain he drew back and remonstrated; for the more he attempted to avoid the honour and to resist, the more strongly did the soldiers in their turn insist upon not accepting an emperor appointed by others but upon giving one themselves to the whole world. Hence he yielded, albeit with apparent reluctance.

4 The consuls for a time sent tribunes and others forbidding him to do anything of the sort, but to submit to the authority of the people and of the senate and of the laws; when, however, the soldiers who were with them deserted them, then at last they, too, yielded and voted him all the remaining prerogatives pertaining to the sovereignty.

2 Thus it was that Tiberius Claudius Nero Germanicus, the son of Drusus the son of Livia, obtained the imperial power without having been previously tested at all in any position of authority, except for the fact that he had been consul. He was in his fiftieth year.

Conquest of Britain

In line with a goal Caesar had failed to meet, Claudius resumed the Roman attempt to conquer Britain. Using a local would-be ruler's request for help as an excuse to invade, with four legions in A.D. 43. [See Timeline.]

"[A] certain Bericus, who had been driven out of the island as a result of an uprising, had persuaded Claudius to send a force thither...."

Dio Cassius 60

Dio Cassius continues with a summary of Claudius' involvement on the scene and the Senate awarded title Brittanicus, which he passed down to his son.

When the message reached him, Claudius entrusted affairs at home, including the command of the troops, to his colleague Lucius Vitellius, whom he had caused to remain in office like himself for a whole half-year; and he himself then set out for the front. 3 He sailed down the river to Ostia, and from there followed the coast to Massilia; thence, advancing partly by land and partly along the rivers, he came to the ocean and crossed over to Britain, where he joined the legions that were waiting for him near the Thames. 4 Taking over the command of these, he crossed the stream, and engaging the barbarians, who had gathered at his approach, he defeated them and captured Camulodunum,13 the capital of Cynobellinus. Thereupon he won over numerous tribes, in some cases by capitulation, in others by force, and was saluted as imperator several times, contrary to precedent; 5 for no man may receive this title more than once for one and the same war. He deprived the conquered of their arms and handed them over to Plautius, bidding him also subjugate p423the remaining districts. Claudius himself now hastened back to Rome, sending ahead the news of his victory by his sons-in‑law Magnus and Silanus. 22 1 The Senate on learning of his achievement gave him the title of Britannicus and granted him permission to celebrate a triumph.

Succession

After Claudius adopted his fourth wife's son, L. Domitius Ahenobarbus (Nero), in A.D. 50, the emperor made it clear that Nero was preferred for the succession over his own son, Britannicus, about three years Nero's junior. There were several reasons for this. Among others, Romm argues that however much Britannicus might seem the obvious successor, his ties to the still important first emperor, Augustus, were weaker than those of a direct descendant, like Nero. Furthermore, Britannicus' mother, Messalina, had never made it to the rank of Augusta, as that was a role that had been reserved for women who were not the wives of currently reigning emperors, but Nero's mother was made Augusta, a title that implied power. In addition, Nero was Claudius' great-nephew, because his mother, Claudius' last wife, Agrippina, was also Claudius' niece. To marry her despite the close familial relationship, Claudius had received special senatorial approval. In addition to the other points in Nero's favor, Nero was betrothed to Claudius' daughter, Octavia, a now sibling relationship that had also required special finagling.

From Tacitus Annals 12:

[12.25] In the consulship of Caius Antistius and Marcus Suilius, the adoption of Domitius was hastened on by the influence of Pallas. Bound to Agrippina, first as the promoter of her marriage, then as her paramour, he still urged Claudius to think of the interests of the State, and to provide some support for the tender years of Britannicus. "So," he said, "it had been with the Divine Augustus, whose stepsons, though he had grandsons to be his stay, had been promoted; Tiberius too, though he had offspring of his own, had adopted Germanicus. Claudius also would do well to strengthen himself with a young prince who could share his cares with him." Overcome by these arguments, the emperor preferred Domitius to his own son, though he was but two years older, and made a speech in the senate, the same in substance as the representations of his freedman. It was noted by learned men, that no previous example of adoption into the patrician family of the Claudii was to be found; and that from Attus Clausus there had been one unbroken line.

[12.26] However, the emperor received formal thanks, and still more elaborate flattery was paid to Domitius. A law was passed, adopting him into the Claudian family with the name of Nero. Agrippina too was honoured with the title of Augusta. When this had been done, there was not a person so void of pity as not to feel keen sorrow at the position of Britannicus. Gradually forsaken by the very slaves who waited on him, he turned into ridicule the ill-timed attentions of his stepmother, perceiving their insincerity. For he is said to have had by no means a dull understanding; and this is either a fact, or perhaps his perils won him sympathy, and so he possessed the credit of it, without actual evidence.

Tradition has it that Claudius' wife Agrippina, now secure in her son's future, killed her husband by means of a poison mushroom on October 13, A.D. 54. Tacitus writes:

[12.66] Under this great burden of anxiety, he had an attack of illness, and went to Sinuessa to recruit his strength with its balmy climate and salubrious waters. Thereupon, Agrippina, who had long decided on the crime and eagerly grasped at the opportunity thus offered, and did not lack instruments, deliberated on the nature of the poison to be used. The deed would be betrayed by one that was sudden and instantaneous, while if she chose a slow and lingering poison, there was a fear that Claudius, when near his end, might, on detecting the treachery, return to his love for his son. She decided on some rare compound which might derange his mind and delay death. A person skilled in such matters was selected, Locusta by name, who had lately been condemned for poisoning, and had long been retained as one of the tools of despotism. By this woman's art the poison was prepared, and it was to be administered by an eunuch, Halotus, who was accustomed to bring in and taste the dishes.

[12.67] All the circumstances were subsequently so well known, that writers of the time have declared that the poison was infused into some mushrooms, a favourite delicacy, and its effect not at the instant perceived, from the emperor's lethargic, or intoxicated condition. His bowels too were relieved, and this seemed to have saved him. Agrippina was thoroughly dismayed. Fearing the worst, and defying the immediate obloquy of the deed, she availed herself of the complicity of Xenophon, the physician, which she had already secured. Under pretence of helping the emperor's efforts to vomit, this man, it is supposed, introduced into his throat a feather smeared with some rapid poison; for he knew that the greatest crimes are perilous in their inception, but well rewarded after their consummation.