For 10 points, name this occupation of Hadrian and Claudius.
In one novel, a man with this occupation watches a "fire festival" and thinks about "millions of lives" succeeding one another like waves. That man plans to "seduce everyone and everything, even history" before his lover drowns himself. Another character with this occupation addresses memoirs to the future after reading a prophecy about "hairy men" and writes a parody about gambling that is taken seriously. A letter to Mark makes up a Marguerite Yourcenar novel titled for the (*) "Memoirs" of a person with this occupation. Another character with this occupation loves the prostitute Calpurnia and hides behind a curtain; that historian is perpetually seen as "a fool" but survives the scheming of Livia. Robert Graves wrote a fictional autobiography about a stammering one of these people. For 10 points, name this occupation of Hadrian and Claudius.
In one novel, a man with this occupation watches a "fire festival" and thinks about "millions of lives" succeeding one another like waves.
Roman emperors [prompt on incomplete answer]