Memoirs of Hadrian is a historical novel in the form of a long letter written by the Roman Emperor Hadrian to his young friend and eventual successor, Marcus Aurelius. Alas, Hadrian is "growing old, and is about to die of a dropsical heart." The Emperor begins by describing his recent visit with his physician Hermogenes, who "was alarmed, in spite of himself, at the rapid progress of the disease" (3). In light of his physical deterioration, Hadrian begins to reflect on his life and work, and to share his wisdom with his young correspondent.

Hadrian tells of his early life as the protégé of the Emperor Trajan, his military and political victories, and his eventual adoption by Trajan, a move that guaranteed the succession when his adoptive father died. While Trajan, whose victories brought the Roman Empire to its greatest size, was a military man to the core, Hadrian considers himself essentially peace loving--his personal life devoted to simplicity and harmony; and his public life to prosperity and justice. Nonetheless, he has always recognized that, in order to govern effectively, ruthless action is sometimes required.

Hadrian's marriage to the Empress Sabina was simply a matter of convenience. The love of his life was a beautiful young man named Antinous. The two men were deeply committed to one another, but at the same time the middle-aged emperor had "a certain dread of bondage" ( 177) that kept him from fully giving himself to Antinous with the abandon of youth. They were visiting Alexandria when the despondent Antinous committed suicide in a way that mimicked a religious ritual, essentially sacrificing himself to the deified Emperor.

Hadrian was crushed with grief and descended into a long period of depression. However, he eventually overcame his depression through his love of literature and ideas, as well as his sense of duty to the Empire (no SSRIs being available at the time), although not before attempting to enlist his physician in assisted suicide. Unable to refuse his emperor's request, the physician himself commits suicide rather than violating his Hippocratic Oath.

Hadrian's final military engagements involve crushing Jewish insurgents in Palestine, completing the destruction of Jerusalem, and founding a new Roman city on its site. The aged Emperor reflects frequently on his tolerance for all religions, except for politically disruptive fanatics like the followers of a Jewish prophet called Christ. As to the Jews in Palestine, he cannot understand why they continue to engage in self-destructive rebellion, most recently with Bar Kokhba and Rabbi Akiva as their leaders.

In his final years Hadrian adopts Lucius, one of his former lovers (in this account), as his son and heir, but Lucius soon dies, presumably from tuberculosis. Eventually, the Emperor adopts Antinous Pius as his heir and further arranges for Marcus Aurelius to succeed Antinous Pius. At the end of his letter, Hadrian writes, "I could now return to Tibur, going back to that retreat which is called illness, to experiment with my suffering, to taste fully what delights are left to me, and to resume in peace my interrupted dialogue with a shade." [i.e. Antinous, his lost love (271)].