to send him away to his death—and Horatio would likely receive some reward or honor for this—but he would never turn on his friend in such a way. After Horatio reads the letter he receives from Hamlet, he immediately takes the actions that Hamlet wants him to. He tells the sailor who delivers the letter,

Come, I will give you way for these your letters,
And do 't the speedier, that you may direct me
To him from whom you brought them (4.6.31–33).

The haste with which he moves to assist his friend demonstrates Horatio's loyalty to Hamlet.

Later, when Osric arrives to challenge Hamlet to a fight with Laertes, Horatio risks displeasing Hamlet in order to protect him. Laertes is well known for his fencing skill, and in his concern for his friend, Horatio tells Hamlet, "You will lose this wager, my lord" (5.2.197). A true and loyal friend will tell the truth, even if he risks his friend's anger, when he is trying to protect that friend, as Horatio is doing here. He also tells Hamlet,

If your mind dislike anything, obey it. I will forestall their
repair hither and say you are not fit (5.1.203–204).

He encourages Hamlet to listen to his own mind and take heed of any reservations that he feels. Horatio even offers to lie for Hamlet and tell everyone that he is not feeling well and so cannot fight. He does not care whom he displeases, as long as he does the best he can for his friend.

Horatio is Prince Hamlet's faithful friend throughout Shakespeare's famous play, Hamlet. There are multiple scenes throughout the play that depict Horatio's loyalty to Prince Hamlet. Towards the beginning of the play in Act I, Scene 5, Hamlet speaks to the ghost of his father and tells Horatio to keep everything that has just happened a secret. Horatio tells Hamlet that he will not say a word, and Hamlet makes him swear to it. Horatio says, "In faith, my lord, not I" (Act I, Scene 5, line 145).

In Act III, Scene 2, Hamlet explains to Horatio that there will be a scene in the play which will depict the circumstances of his father's death. Hamlet then asks Horatio to watch Claudius closely and gauge the king's reaction during the scene. Horatio loyally responds by telling Hamlet that he will stare at Claudius the same way he would watch a thief. Horatio comments, "Well, my lord. If he steal aught the whilst this play is playing, And 'scape detecting, I will pay the theft" (Act III, Scene 2, lines 81-83).

During Act V, Scene 2, Hamlet is dying and asks Horatio to tell the tragic story to the citizens of Denmark. Horatio responds by saying, "Never believe it. I am more an antique Roman than a Dane. Here's yet some liquor left" (Act V, Scene 2, lines 336-38).

Horatio demonstrates his loyalty by attempting to commit suicide alongside his friend, Prince Hamlet. Prince Hamlet drinks the poison instead, and Horatio laments at his friend's death. Horatio says, "Now cracks a noble heart.---Good night, sweet prince, and flights of angels sing thee to thy rest!" (Act V, Scene 2, line 359).

1. Act I, Sc. 2

HORATIO
As I do live, my honour'd lord, 'tis true;
And we did think it writ down in our duty
To let you know of it

Horatio feels that it is duty to inform Hamlet that he has seen the ghost of Hamlet's father.

2. Act II, Sc. 4

What if it tempt you toward the flood, my lord,
Or to the dreadful summit of the cliff
That beetles o'er his base into the sea,
And there assume some other horrible form,
Which might deprive your sovereignty of reason
And draw you into madness?

Horatio urges Hamlet not to follow the Ghost because it may harm him.

3. Act I, Sc. 5

HAMLET 
And now, good friends,
As you are friends, scholars and soldiers,
Give me one poor request.

HORATIO
What is't, my lord? we will.

HAMLET
Never make known what you have seen to-night.

HORATIO MARCELLUS
My lord, we will not.

HAMLET
Nay, but swear't.

Horatio swears to Hamlet that he will not reveal Hamlet's meeting with the Ghost.

4. ACT V, Sc. 2

HORATIO: I am more an antique Roman than a Dane. Here's yet some liquor left.

After seeing that Hamlet has been wounded with the poison sword, Horatio says that he will commit suicide rather than outlive his friend Hamlet.  This is in accordance with ancient Roman ideas based on the Greek philosophy of Stoicism.