"Not even at the bed of his sick father can Shakespeare's Prince Hal avoid the temptation of trying on the crown to see how it suits him"

   A reference to Act IV Scene Five of William Shakespeare's Henry IV, Part One, in which Prince 'Hal' prematurely dons the crown of England. His excuse, that he momentarily thought his father dead, only enrages the king further:

Thy wish was father, Harry, to that thought

 

Online text of the play at MaximumEdge.com