Pompeia

Pompeia was Julius Caesar's wife. Caesar divorced her after a man named Clodius managed to enter her Bona Dea festival. This was because the Roman ruler insisted that his wife must be always be "above suspicion" — it could not be proven that nothing had gone on at the party, and so she could not remain his wife.

The phrase "Caesar's wife" later came to mean "someone who's pure, perfect [and] above suspicion", though the Fourth Doctor took issue with this common understanding of the phrase. (PROSE: Sarah Jane and the Temple of Eyes)