What sad events turned Hamlet into very unhappy young man?

Because
we do not meet before the plays action begins, we cannot be sure that he was not always the
melancholy Dane. By the time we meet him, he is certainly unhappy. Two events are mainly the
cause of his misery, but it is compounded by a third. First and foremost is the death of his
father, also named . Second, which followed shortly thereafter, is the marriage of his mother, ,
to his uncle and fathers brother, . Hamlet strongly suspects, and spends much of the play
getting the evidence to prove, that Claudius murdered Hamlet Senior. He is alerted to this idea
by the third event, the appearance of his fathers ghost to tell him what transpired. Also
related, but not an event, is Hamlets emotional state: he becomes overwhelmed by guilt as the
evidence eludes him and he is unable to take revenge on Claudius.