How is friendship and loyalty a theme in "Hamlet"?

The theme of friendship and loyalty is seen through the relationship between Hamlet and Horatio. Horatio is the only character that Hamlet can truly trust during the play. He was a student at Wittenburg where Hamlet studied and comes all the way from Germany for the funeral of Hamlet's father. His loyalty and friendship to Hamlet are unquestioned. Even at the beginning of the play, the guards recognize this and Horatio is the one who they turn to when they see the ghost. Horatio is the only person Hamlet trusts to reveal his suspicions about Claudius. Before seeing Claudius' reaction to "The Murder of Gonzago", Hamlet praises his friend. He says,

"For thou hast been

As one, in suff'ring all, that suffers nothing;

A man that Fortune's buffets and rewards

Hast ta'en with equal thanks; and blest are those

Whose blood and judgment are so well commeddled(65)

(Act III, scene ii lines 54-65)

He adds:

"Give me that man

That is not passion's slave, and I will wear him

In my heart's core, ay, in my heart of heart,

As I do thee."

( Act III, scene ii, Lines 67-69)

Even Claudius trusts Horatio to look after Hamlet after Hamlet's encounter with Laertes at Ophelia's funeral. In the end, Horatio proves to be a very loyal friend when he is willing to die alongside Hamlet. However, Hamlet has a better plan for him. He asks Horatio to tell his story and thus preserve the lessons of his life for posterity. So Horatio agrees and becomes the perfect example of a loyal friend.