Gaius Octavius (63 BCE – 14 CE), great-nephew and heir of Julius Caesar; after the defeat of Antony and Cleopatra (31 BCE), sole ruler of Rome. From 27 BCE "Augustus"; the founder of the principate that ended the Republic. He ruled 41 years and left the image of the founder of the imperial order; after death he was deified. For Marcus he is not kin but the ultimate measure of power and fame: if even his court is long dead, then any care for posthumous greatness is the emptier.

A standing exemplum of the transience of power, most often paired with Hadrian:

• 08-05 — "soon you will be nobody and nowhere, like Hadrian and Augustus": two limiting images of power swallowed by time.
• 08-31 — "the court of Augustus" (Αὐλὴ Αὐγούστου): wife, daughter, Agrippa, Maecenas — the whole brilliant circle "died out entire."
• 04-33 — "then Augustus, then Hadrian and Antoninus": even the greatest names become "glosses" and sink into oblivion.
• As a cross-reference — also in 06-56 and 04-32 (allusions to the "court of Augustus" from 8.31).