Why do surviving documents suggest that ancient historians gave a one-sided picture of Claudius?

Ancient historians, including Tacitus, Suetonius, and Dio Cassius, provided a one-sided, negative portrayal of Claudius largely because they echoed the hostility of the Roman upper classes toward him.1

Although Claudius often paid lip service to the dignity of the Senate, his policies frequently favored the army, freedmen, and provincial administration over the interests of the senatorial aristocracy. Consequently, these historians attributed his perceived failures to personal character flaws and the influence of his wives and freedmen.12

This biased tradition is contradicted by surviving administrative documents—such as inscriptions and official letters—which reveal a ruler who was energetic, capable, and deeply engaged in the complexities of government. Works like the Apocolocyntosis, written by political rivals, further solidified this distorted image by ridiculing his physical appearance and judicial decisions, prioritizing satire over objective historical record.1