In A.D. 33 Asinius Gallus was starved to death and his memory damned, even though he had not been convicted of any crime. In their attempts to rationalise his demise, Tacitus and Dio tell us that Gallus had exploited his marriage to Tiberius’ ex-wife Vipsania in a way which Tiberius found offensive, but they provide no details. In this paper I propose that a monumental dedication to Agrippa at Ephesus can be read as evidence of just such an offence by Gallus, and that his shocking fate was Tiberius’ long-delayed revenge for the insult that the dedication represented.