Concepts for powerful undead ruling over live subjects

[Black Leviathan]

The college of the dead: For centuries members of a scholastic order have been ritually decapitated after death and their head ensconced in a crypt animated in death to continue their debates and to ensure their wisdom is not lost to the future. They are gatekeepers of profound knowledge but death has made them strange.

The Divine Ruler: He was dictated by the gods to rule on earth and that mandate is not challenged by death. Upon his collapse he had is body wrapped and his organs removed per ancient rite and his body re-animated. He continues his glorious rule from beyond life, his heirs set aside to one day join him and princes and princesses eternal, clothing of gold and jewels draped over a noble corpse king.

The humble Duke: This profoundly kind ruler loved nothing in life more than the good people who he ruled over. He wanted to live a long life watching their fortunes better themselves and to watch his Dukedom grow in harmony and bounty. Cruel fate infected him with a wasting disease and no heir. Refusing to surrender his people to chaos and oppression the Duke made a bargain with a necromancer to transform him into a lich that he might continue to rule. Now he sits on his throne with no heir in sight, struggling against entropy to provide fair rule to the good people of his lands, hoping some year to find a worthy successor to his rule.

[Johnny Angel]

I think this has been somewhat touched upon by other ideas, but a group of elves in D&D's Eberron setting are ruled/advised by (un)living ancestors, who have voluntarily sacrificed their death and ascent into the afterlife by becoming undead and sticking around to guide the society.

I may be a little off on the details. I have not played the setting for a long time.


Edit: The Undying Court