Why did Catullus write insulting poems about Julius Caesar?

Catullus wrote insulting poems about Julius Caesar as part of a broader tradition of invective poetry, which he used to express contempt or hatred toward various figures, including Caesar, his son-in-law Pompey, and his military engineer Mamurra.123

While the exact motivations behind these specific attacks are not explicitly detailed in historical records, his work is noted for its satiric humor and obscenity, which he defended as a serious literary convention. Despite the harshness of these poems—which Caesar himself acknowledged were personally damaging—the two maintained a complex social relationship. Notably, Catullus’ father was a friend and host to Caesar, and after the poet lampooned him, Caesar responded with clemency, inviting Catullus to dinner the same day he received an apology.32

Ultimately, these poems reflect Catullus' broader tendency to challenge traditional Roman mores and deflate the pretensions of powerful figures during the final years of the Roman Republic.34