I am not sure if this is what you mean by your question, but this play serves as a warning to all kings: THIS IS WHAT A KING IS NOT! So, when you say it is "fit for the Kings" I believe this means that kings should pay attention to the lessons of the play.
In the play, the king, Duncan, is a good king. He is killed by Macbeth, who is not a good king, but blindly ambitious and power hungry. Duncan was well-loved because he cared about his people. Macbeth only cares about himself and his power. After Duncan is killed, he is still referred to as "the king" whereas Macbeth is referred to with many negative words, including "tyrant"
This tyrant, whose only name blisters our tongues,
Was once thought honest.
In Act IV, Scene III, Macduff goes to England to meet with Malcom, Duncan's son. Malcolm does not trust anybody, since his father has been killed, and he wants to see if Macduff is loyal to Scotland, so he tests him by pretending that he would not be a very good king. He tells Macduff:
I have no knowledge
Of the king-becoming graces, such as justice, verity,
Temperance, stableness, bounty, perseverance,
Mercy, lowliness, devotion, patience, courage, fortitude,
Macduff is dismayed when Malcolm outlines all the reasons he would be a bad king and mourns for Scotland:
O nation miserable,
With an untitled tyrant holding a bloody scepter,
When Malcolm hears this, he knows that Macduff is loyal, and he tells Macduff that he was only testing him, that he would be a good king and is ready to fight Macbeth:
I have never gone back on my word,
Scarcely have wanted what was my own,
At no time broke a promise, would not betray
The devil to his fellow, and delight
More in truth than life. My first lie ever
Was these things I said about myself. What I am, truly,
Is your and my poor country's to command,
Where, indeed, before you came here,
Old Siward, with ten thousand warlike men
Already at a point, was coming to.
Now we'll fight together, and the chance of goodness
Will like our necessary quarrel!
In their discussion, the qualities of good kings are outlined, so this defines what a good king should be.
If this is not what you are asking, please re-post your question and be more specific about what you mean by "fit for Kings."
WRONG WEONG ANS!!!!!!!!!!!!!!!!!!!!!!
thanks a lot lynnebeh....
the material was really helpful.. thanks