The poem centers on the brutal conflict between Julius Caesar and Pompey the Great as the Roman Republic descends into internal collapse. Lucan follows the political and military maneuvers of the two primary antagonists, detailing the erosion of Roman values and the physical destruction of the state. The narrative framework utilizes epic verse to document the shift from democratic governance to autocratic rule. The protagonist, if one can be identified in such a fractured landscape, is the Roman state itself, struggling against the logical constraints of inevitable civil ruin and the hubris of its leaders.

Readers and critics frequently note the grim, realistic tone that distinguishes this work from more idealized Roman epics. Discussion often centers on Lucan's departure from traditional mythological tropes in favor of a stark, historical focus on the horrors of internal conflict. Scholars highlight the effectiveness of his writing in conveying the psychological weight of the Roman state's self-inflicted destruction. The text is often analyzed for its influence on later political literature and its unique position within the Latin canon.