What is the relationship between prince fortinbras and king fortinbras? Is it a good relationship? What goes on in the relationship?
As in the eponymous Hamlet's case, much of what Prince Fortinbras does in this play is connected to his father. Also as in Hamlet's case, the relationship between father and son is a very important one, but one which is dominated by the father's absence.
Prince Fortinbras' relationship with his father cannot really be said to be either "good" or "bad," as, from what we know, the two were never able to have an adult relationship at all. However, it is certainly the case that Prince Fortinbras' life has been greatly influenced by his father and what happened to him, as he was killed when his son was very young as a result of a bet with Hamlet's father, King Hamlet.
Just as Hamlet is driven to seek revenge for his own father's death, Fortinbras is driven to avenge his own father, but chooses perhaps a more productive way to do it. In his defeat, King Fortinbras lost a portion of his land; Prince Fortinbras, therefore, is set upon reclaiming this territory. This is what drives his invasion against the "Polack" (Poland).
King Fortinbras was killed when his son, Young Fortinbras was a boy. King Fortinbras' uncle, named Old Norway in the play, took over as King. Young Fortinbras never really knew his father but blamed King Hamlet ( young Hamlet's father) for his own father's death. When the play opens, young Fortinbras has grown up and raised an army to get back the lands that his father lost to King Hamlet. According to the gravedigger, Delver, young Hamlet was born on the day that King Fortinbras was killed.