Emperor Claudius ruled the Roman Empire from 41 to 54 AD. He was the nephew of Emperor Tiberius and became emperor after the assassination of Caligula. Despite being considered an unlikely leader due to his physical disabilities and perceived weaknesses, Claudius proved to be an effective administrator and expanded the empire. During his reign, Claudius initiated significant reforms, including improvements in the legal system and infrastructure. He is also known for the conquest of Britain, which marked a major expansion of Roman territory. Claudius's reign ended with his death, possibly due to poisoning, leading to the rise of Nero.