Tiberius Claudius Nero Germanicus (10 BC - AD 54) became the unlikely 4th emperor of the Julio-Claudian line after the violent murder of his nephew Gaius (Caligula). The reign of Claudius is important for several reasons. He stabilized the political environment by including provincials in the Senate rolls (even though he was vilified for it), and proved an effective re-establishment of the imperial line after the debacle of Caligula. He made several provincial annexations, including the conquest of Britain which brought vital new sources of precious metals under Roman control. Despite these positives, depending on one's perspective, of course, he was the first emperor to rise to his position through assassination and praetorian political intervention. Once the precedent was set, it became a regular occurrence throughout the principate period. Also of important note, Claudius was terribly slandered by the ancient sources, not only for his physical characteristics and mannerisms, but for his political activities. He propped up favorite free or freedmen into important positions of government authority and, at least on occasions, fell under the influence of various people of doubtful political agendas. Perhaps worst of all, Claudius ignored his own son in the imperial hierarchy, favoring the son of his 4th wife and niece, Agrippina. Claudius gave the world Nero, perhaps the worse of the Roman emperors, apparently from his own free choice, rather than continue the Julio-Claudian line with some semblance of stability.
Claudius was born at Lugdunum in Gaul to Antonia (daughter of Mark Antony and niece of Augustus) and Drusus Claudius Nero, the second son of Livia, Augustus' wife. His brother, the great Germanicus, would become one of the most popular figures in early imperial Rome, while Claudius was mired in near anonymity or family scorn, if not for one fateful assassination. Claudius was born with several birth defects, the cause of which are speculated (perhaps the tradition of family epilepsy, or cerebral palsy, etc.), but completely improvable. Despite his obvious family connections, these defects kept him labeled as far inferior, both physically and mentally. Even as a boy, he limped, drooled and stuttered profusely. In the tradition of Augustus, he was also commonly ill in his youth, and while it may be seen as miraculous that he could've survived in the cutthroat imperial world, it may have ensured his survival by virtue of being completely ignored. He was generally perceived as an idiot and was kept on the outskirts of the imperial family. Rather than assume his rights as a man upon the proper age he was kept under continued guardianship, like a young women of the time would have been. The majority of his early life was kept in complete seclusion, and he was not brought into the political fold the way 'normal' boys of the family line had been. Instead, Claudius prepared for the unlikely political power to come by reading and studying himself into perhaps one of the foremost historical scholars of the day. Among his works were 43 books of Roman history, 21 books of Etruscan history, and 8 on Carthage. Unfortunately, all of these along with an additional 8 autobiographical books (which have been recreated in the vastly popular fictional novels 'I, Claudius' and 'Claudius the God' by Robert Graves) are lost to history.
Politically, the only post that Claudius was appointed to before the accession of Caligula was that of a minor priest, or an augur. During the purges of Sejanus, under Tiberius' reign (Claudius' uncle), the Claudian family suffered heavily, with Caligula, his sisters and Claudius emerging as the only survivors of note. While Claudius was likely deeply involved in his own personal studies in the mid 40's of life, Tiberius died and Caligula's accession finally brought the family black sheep into the public spotlight. Caligula made his uncle a suffect consul in 37 AD, but seemed to do so out of a preference for Claudius' presence as a target of jokes and cruelty, rather than value his political skill or opinion. Regardless, within the fast and furious four years of Caligula's rule, Claudius must have established himself to some end politically, if only to set the stage for an effective reign of his own.
On January 24, AD 41, Caligula was cut down by members of the Praetorian Guard, and in the mayhem that followed Claudius was supposedly discovered hiding behind some curtains within the palace. In this version of the story, the one which Claudius himself seemingly preferred (which painted him as a completely innocent and unassuming victim, rather than a part of any plot), Claudius was carried off to the Praetorian camp to keep him safe, while the matter of true succession was formulated. Though the Senate attempted to gain control for itself, the Praetorians, whose viability depended on an Imperial regime in order to survive as a legitimate entity, remained loyal to the Principate concept. With the Praetorians, and therefore the bulk of the legions firmly behind Claudius, the Senate had no choice but to accept Claudius as the new 'emperor'. The bumbling, stumbling, drooling fool, as he was commonly known, had supposedly stepped out from behind the curtain into the most powerful and politically important position in the western world. However, though evidence is circumstantial at best, there is growing sentiment that Claudius himself may have had more involvement. While this can never be proven, the circumstances of the events just seem a bit too convenient. Regardless, he was shortly 'approved' to his new imperial position, and quickly set about a complete shake up of the status quo, and his own public perception.