This article discusses the relationship of Tacitus to his younger contemporary Suetonius, challenging the view that Suetonius wrote a ‘supplement’ to the historian. Scholarly focus on this pair has led to the widespread belief that Suetonius had read Tacitus’ Annals, which is unsupported by the evidence. The prevailing consensus that the biographer may at times be subtly criticizing the historian persists in commentaries on Suetonius’ Caesars. It is argued that where their two accounts appear to meet, Suetonius is better seen as responding to the earlier common source or sources, or distinguishing himself from the conventions of historiography at large.