Final answer:
Caligula was known for radical decision-making, such as hosting games where senators were charioteers and appointing his horse as a high priest, which illustrated his unpredictable governance. He also became notorious for his cruelties post-illness in 37 CE, with actions that included needless military parades and harsh treatment of the Senate.
Step-by-step explanation:
Caligula's rule is infamous for its radical decision-making and extreme measures. Notoriously, he hosted lavish games in the Circus, including a race where the charioteers were senators, creating a unheard of spectacle blending entertainment with a subtle assertion of his power over the Roman elite. Similarly, Caligula's personal behavior illustrated his megalomania, such as his preference to appear in public dressed as various gods or goddesses. This tendency towards autocracy culminated in moves like the absurdity of appointing his horse, Incitatus, as a high priest and even as a consul, an action emblematic of his unpredictable governance and contempt for traditional Roman political structures.
Beyond public spectacles, Caligula's tenure was marked by acts of cruelty and sadism, especially following a severe illness in 37 CE. Post-illness, Caligula's behavior became increasingly erratic, with him spending vast sums on construction projects and luxurious dwellings and staging needless military parades to demonstrate his power. His treatment of the Senate, ordering treason trials and executions, illustrated a degradation of the previous political order and a shift toward autocracy that would only end with his assassination in 41 CE by disgruntled members of the Praetorian Guard and the Senate.