William Shakespeare 
The Tragedy of Hamlet, Prince of Denmark 

In The Tragedy of Hamlet, Prince of Denmark, Hamlet is mourning the death of his father, the King of Denmark. He is angry about the sudden marriage of his mother, Queen Gertrude, to his uncle, Claudius. One night, the king's ghost visits Hamlet. He tells his son that Claudius was the one who killed him. Hamlet vows to avenge his father's death.