Following the death of the elderly emperor Nerva, Trajan, then serving as a provincial governor and army commander on the Rhine frontier, became emperor of Rome. His nineteen-year reign brought the empire to its largest territorial extent, conquering Dacia and pushing into Mesopotamia, while his building programs left lasting monuments including Trajan's Column and Trajan's Market.
Trajan was the first Roman emperor born outside Italy, hailing from the Roman colony of Italica in southern Spain, a fact that reflected how thoroughly Roman citizenship and power had spread beyond the Italian peninsula by the end of the first century. Nerva, his elderly predecessor, had adopted him as successor under pressure from the military after a brief and unstable reign, seeking a strong general to secure the throne.
Once in power, Trajan proved a formidable and popular ruler, later remembered by the Roman Senate with the acclamation 'may he be luckier than Augustus and better than Trajan,' a formula later emperors hoped to earn. He personally led campaigns that conquered Dacia (modern Romania), funding a massive column in Rome carved with spiraling reliefs depicting the wars, and pushed Roman borders to their absolute maximum extent by annexing Armenia and Mesopotamia.
His reign is often cited by historians, including Edward Gibbon, as part of the high point of the Pax Romana, an era of relative peace and prosperity under the 'Five Good Emperors.' His extensive public building programs, aqueducts, and support for orphans and the poor through the alimenta program made him a model of benevolent autocracy still studied for its blend of military ambition and civic administration.