In ancient Rome, social appearance and respectability were everything. The most hated men were punished with damnatio memoriae, damnation of memory. Every trace that a person had ever lived was removed. Busts were shattered, freizes were marred, records were struck. Any sign of the hated figure was destroyed.
A culture has it forbidden to say their rulers name under penalty of death. Anybody in power must be referred to as their title. Comes from the fact that the rule or position can be taken over by anybody from any level in society. To use the title elevates them or brings them down from whatever level they were originally at before they took the position. Respect and authority comes from the position, not from previous life.