The Meditations of Marcus Aurelius has so much useful advise...

[47of74]

"Never value anything as profitable to thyself which shall compel thee to break thy promise, to lose thy self-respect, to hate any man, to suspect, to curse, to act the hypocrite, to desire anything which needs walls and curtains: for he who has preferred to everything intelligence and daemon and the worship of its excellence, acts no tragic part, does not groan, will not need either solitude or much company; and, what is chief of all, he will live without either pursuing or flying from death; but whether for a longer or a shorter time he shall have the soul inclosed in the body, he cares not at all: for even if he must depart immediately, he will go as readily as if he were going to do anything else which can be done with decency and order; taking care of this only all through life, that his thoughts turn not away from anything which belongs to an intelligent animal and a member of a civil community." - Marcus Aurelius, Meditations.

[Fortinbras Armstrong]

1. Marcus Aurelius can reasonably be called a Philosopher King

Thomas Jefferson might also qualify. Who else?

[Odin2005]

2. Ashoka Maurya of ancient India?

He converted to Buddhism out of guilt from his bloody conquests.

[Odin2005]

3. Unfortunately his son was a vain asshole who fucked over the Empire.