Emperor Claudius was born on August 1, 10 BC, in Lugdunum, the city now known as Lyon, France. Augustus was the reigning emperor of Rome at the time of his birth.

His father was Nero Claudius Drusus, known to history as Drusus the Elder, a Roman military commander. His mother was Antonia Minor, the daughter of Mark Antony and Octavia.

Claudius entered the world as a member of the imperial family, but nothing about his early years suggested he would ever lead it. He was the nephew of the emperor Tiberius, the brother of the celebrated general Germanicus, and the uncle of Caligula. He would not become emperor until AD 41, following Caligula’s assassination.

Before that moment arrived, Claudius had been kept almost entirely out of public life. A limp and a speech impediment led his family to conclude he was too weak and too intellectually limited for political or military responsibility, a judgment they acted on by marginalizing him from the world most men of his station were expected to inhabit.

He spent those years in private study and writing. He produced works on Roman history, Etruscan history, and Carthaginian history, most of which have not survived. He lived quietly and largely in the shadow of his more celebrated relatives.

When Caligula was killed in AD 41, Claudius was fifty years old and had no real experience of governance. The manner of his elevation was not exactly dignified: soldiers searching the palace after the assassination found him hiding and declared him emperor on the spot.

As emperor, Claudius accomplished considerably more than anyone had predicted.

His most celebrated achievement was the conquest of Britain. In AD 43, he dispatched Roman armies to invade the island, and Britain became a Roman province. The success raised his standing with the military and with the broader Roman public.

He also demonstrated genuine administrative competence. Claudius brought experienced advisors and freedmen into the machinery of government and used them to run the empire with greater efficiency than his predecessors had managed in certain areas. He gave attention to the legal system and to ensuring that laws were applied with some degree of consistency.

His building program was substantial. Roads, aqueducts, and canals were constructed across the empire to support commerce and improve daily life. A new harbor at Ostia improved the flow of goods into Rome and helped stabilize the grain supply. The empire also expanded under his watch in parts of North Africa and the Middle East.

Thirteen years of rule left Rome more organized and better administered than Claudius had found it. That outcome confounded the expectations of everyone who had dismissed him.

His reign also had serious failures.

His willingness to trust the wrong people was a persistent vulnerability. He leaned heavily on his freedmen advisors, particularly Pallas and Narcissus, and on his wives, and some of those relationships were exploited. Their growing influence made Claudius appear easily managed and reflected poorly on his authority.

His most damaging personal decision was his marriage to Agrippina the Younger in AD 49. She was his own niece, and she was also intensely ambitious. Her goal was to secure the succession for her son Nero rather than for Claudius’s biological son Britannicus. She pressed Claudius to adopt Nero and designate him as heir, and he complied, setting aside his own child’s claim in the process. The consequences of that choice outlasted Claudius himself.

His relationship with the Senate was also troubled. He frequently bypassed the Senate in favor of his own judgment or that of his freedmen, which senators experienced as a dismissal of their institutional role. Resentment accumulated.

His suspicion of plots, some real and some not, led him to order the deaths of a significant number of senators and members of the nobility. Whether the accusations that drove those executions were always legitimate is another matter. The effect was to make him feared among the class he most needed to manage carefully.

Claudius died in AD 54. The prevailing view among ancient historians, and many modern ones, is that Agrippina poisoned him to clear the path for Nero’s accession. His failure to hold his own position against his wife and to protect his son’s future resulted directly in one of Rome’s most disastrous imperial reigns.