Claudius (1 August 10 BC-13 October 54 AD) was the Emperor of the Roman Empire from 41 to 54, succeeding Caligula and preceding Nero. He became emperor on the murder of his nephew Caligula in 41, with the Praetorian Guard prefect Cassius Chaerea proclaiming him the new Caesar immediately afted slaying Caligula; he reigned for thirteen years, and he conquered Britannia during his reign. He was poisoned by his wife in 54 and succeeded by his son Nero.
Claudius was the son of Roman general Nero Claudius Drusus and Antonia Minor, born in Lugdunum, Gaul (present-day Lyon, France). While he was young, he fell ill and gained a limp and slight deafness, causing his family to ostracize him and refuse to give him a public office. During the purges of Emperor Tiberius and his grand-nephew Caligula, Claudius survived due to his weakness; he was the last man of his family by the time of Caligula's death in 41 AD. Claudius was dim-witted, and he was close to his uncle Tiberius during his exile in Capri from 23 to 37; Claudius, Tiberius' grand nephew Caligula, and Caligula's stepbrother Tiberius Gemellus were Tiberius' only remaining family members. When Tiberius was murdered by Naevius Sutorius Macro in 37 AD, Caligula became the new emperor, and he decided to feign interest in maintaining Rome's old status as a democracy by making the incapable Claudius his co-consul. Claudius was dim-witted and did little during Caligula's time as emperor, instead being on the sidelines of the political crises that occurred during Caligua's reign.
The Praetorian Guard, who assassinated Caligula in 41 AD, acclaimed Claudius as the new emperor after finding him hiding from them behind some curtains, and Claudius ironically proved to be a good administrator as emperor. In 43 AD he began the Roman conquest of Britain, a process that lasted until 84, and the Roman legions left Gaul to besiege Britannia and conquer the island (up to the border with Scotland). Claudius issued twenty edicts a day, and he was constantly forced to consolidate his power by killing several senators; this earned him the scorn of the Roman Senate, which viewed this as tyrannical. His niece and fourth wife Agrippina the Younger, the sister of the late Caligula, poisoned him in 54 in favor of their son Nero, who became the new emperor on Claudius' death.