Roman emperor Nerva is forced by the Praetorian Guard to adopt general Marcus Ulpius Trajanus as his heir and successor.

AD 97 (XCVII) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Rufus. The denomination AD 97 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Nerva was a Roman emperor from 96 to 98. Nerva became emperor when aged almost 66, after a lifetime of imperial service under Nero and the succeeding rulers of the Flavian dynasty. Under Nero, he was a member of the imperial entourage and played a vital part in exposing the Pisonian conspiracy of 65. Later, as a loyalist to the Flavians, he attained consulships in 71 and 90 during the reigns of Vespasian and Domitian, respectively. On 18 September 96, Domitian was assassinated in a palace conspiracy involving members of the Praetorian Guard and several of his freedmen. On the same day, Nerva was declared emperor by the Roman Senate. As the new ruler of the Roman Empire, he vowed to restore liberties which had been curtailed during the autocratic government of Domitian.

The Praetorian Guard was the imperial guard of the Imperial Roman army that served various roles for the Roman emperor including being a bodyguard unit, counterintelligence, crowd control and gathering military intelligence.

Trajan was a Roman emperor from AD 98 to 117, remembered as the second of the Five Good Emperors of the Nerva–Antonine dynasty. He was a philanthropic ruler and a successful soldier-emperor who presided over one of the greatest military expansions in Roman history, during which, by the time of his death, the Roman Empire reached its maximum territorial extent. He was given the title of Optimus by the Roman Senate.