Explanation: The North-African-born Roman Emperor Septimius Severus came to his position after The Year of 5 Emperors, one of the many civil wars Rome suffered from in its later years. He ensured his position by being all things to all people - to the soldiers, he was the man of Order who would Set Things Right; to the people, he was the charitable-but-stern father of the nation; to the Senate, he was but the humble servant of the people's (read: RICH people's) will.
Of course, he was really none of those things. What he was was an extremely shrewd and calculating man who knew how people ticked. Dangerous, in other words. The kind of man who, during a brutal civil war, can claw his way to the top position. During his rise to power, he promised that he would not be like the unpopular Emperor Commodus before him - he would never put to death a Senator himself; the right of trying a Senator belonged only to the Senate, not the Emperor!
... no points for guessing whether that particular promise lasted.