Politics is all about trust!

Explanation: In The Year of the Five Emperors, a civil war during the Roman Empire, three of the claimants were the Italian-born Pescennius Niger, and the North African-born claimants Clodius Albinus, and Septimius Severus. Severus promised to make Albinus his heir in exchange for teaming up against Pescennius Niger. Provincial solidarity!

… he had no intention of keeping that pledge, and killed Albinus and made his sons his heirs as soon as he had consolidated power.

As an additional bit of trivia, Pescennius’s name means ‘black’ because his neck was darker than the rest of his body (which was largely pale); his father’s name was ‘Fuscus’ (brown) probably for a similar reason. Likewise, Albinus means ‘white’. While Septimius Severus and Clodius Albinus were both born in North Africa, only Severus was noted as being mixed-race.