Trajan ( TRAY -jən; born Marcus Ulpius Trajanus , adopted name Caesar Nerva Trajanus ; Latin: Caesar Nerva Traianus ; 18 September 53 – c. 11 August 117) was Roman emperor from 98 to 117, one of the Five Good Emperors of the Nerva–Antonine dynasty. He was a philanthropic ruler and a successful soldier-emperor, who led the Roman Empire to its greatest territorial extent by the time of his death. He was given the title of optimus ('the best') by the Roman Senate.

Trajan was born in Italica, close to modern Santiponce (Seville) in present- day Spain, a small Italic settlement in Hispania Baetica; his branch of the Ulpia gens, the Ulpii Traiani , came from the town of Tuder in the Umbria region of central Italy. His father, Marcus Ulpius Traianus, also from Italica, was a senator. Trajan rose to prominence during the reign of Domitian. In 89, serving as a legatus legionis in Hispania Tarraconensis, he supported the emperor against a revolt on the Rhine led by Antonius Saturninus. He then served as governor of Germania Superior and Pannonia. In September 96, Domitian was succeeded by the elderly and childless Nerva, who proved to be unpopular with the army. After a revolt by members of the Praetorian Guard, Nerva decided to adopt as his heir and successor the more popular Trajan, who had distinguished himself in military campaigns against Germanic tribes.

As emperor of Rome, Trajan oversaw the construction of building projects such as the forum named after him, the introduction of social welfare policies such as the alimenta , and new military conquests. He annexed Nabataea and Dacia, and his war against the Parthian Empire ended with the incorporation of Armenia, Mesopotamia, and Assyria as Roman provinces. In August 117, while sailing back to Rome, Trajan fell ill and died of a stroke in the city of Selinus. He was deified by the senate and his successor Hadrian (Trajan's cousin). According to historical tradition, Trajan's ashes were entombed in a small room beneath Trajan's Column.

*[c.]: circa