Why does Claudius send for Rosencrantz and Guildenstern?

King Claudius of Denmark sends for Rosencrantz and Guildenstern in order to find out what is troubling Prince Hamlet and to try to determine the cause of his strange behavior. Claudius hopes that by sending for his childhood friends, Rosencrantz and Guildenstern, he will be able to find out what is bothering Hamlet and hopefully restore him to his former self. Additionally, Claudius may also be using the visit as an opportunity to gather information and spy on Hamlet, as he is suspicious of the prince's motives and fears that he may pose a threat to his own power.

He hopes that by spending time with Hamlet, they will be able to glean some information that could help them find a remedy for his condition. He also hopes that they will be able to provide some entertainment for Hamlet, as he has recently lost all his mirth and is not interested in the company of man or women. Additionally, Claudius is aware of the great love the general public has for Hamlet, and he hopes that Rosencrantz and Guildenstern will be able to use their influence to help him understand the source of Hamlet's distress and find a way to remedy it. Furthermore, Claudius is aware that the actors have arrived and hopes that they will be able to provide some distraction for Hamlet and help him to regain his mirth. He also hopes that they will be able to provide insight into the current state of the theater, as it has changed since Hamlet was last in the city.

Here are the top passages from Hamlet related to the question:

Scene 2

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[Flourish. Enter King and Queen, Rosencrantz and

Guildenstern and Attendants.]

KING

Welcome, dear Rosencrantz and Guildenstern.

Moreover that we much did long to see you,

The need we have to use you did provoke

Our hasty sending. Something have you heard

Of Hamlet's transformation, so call it,

Sith nor th' exterior nor the inward man

Resembles that it was. What it should be,

More than his father's death, that thus hath put him

So much from th' understanding of himself

I cannot dream of. I entreat you both

That, being of so young days brought up with him

And sith so neighbored to his youth and havior,

That you vouchsafe your rest here in our court

Some little time, so by your companies

To draw him on to pleasures, and to gather

So much as from occasion you may glean,

Whether aught to us unknown afflicts him thus

That, opened, lies within our remedy.

QUEEN

Good gentlemen, he hath much talked of you,

And sure I am two men there is not living

To whom he more adheres. If it will please you

To show us so much gentry and goodwill

As to expend your time with us awhile

For the supply and profit of our hope,

Your visitation shall receive such thanks

As fits a king's remembrance.

ROSENCRANTZ  Both your Majesties

Might, by the sovereign power you have of us,

Put your dread pleasures more into command

Than to entreaty.

GUILDENSTERN  But we both obey,

And here give up ourselves in the full bent

To lay our service freely at your feet,

To be commanded.

KING

Thanks, Rosencrantz and gentle Guildenstern.

QUEEN

Thanks, Guildenstern and gentle Rosencrantz.

And I beseech you instantly to visit

My too much changed son.--Go, some of you,

And bring these gentlemen where Hamlet is.

GUILDENSTERN

Heavens make our presence and our practices

Pleasant and helpful to him!

QUEEN  Ay, amen!

[Rosencrantz and Guildenstern exit

with some Attendants.]