What were prominent themes in William Shakespeare's works?

This question is certainly very open-ended and certainly not specific.  I will attempt to give you some ideas of themes Shakespeare explores in multiple works, though he does so in different ways and to different extents.  One important theme Shakespeare explores not only in his tragedies but also in his history plays is "knowledge is power."  In The Tempest, Shakespeare creates a character in Prospero who apparently has the advantage of knowledge over the other characters.  In doing this, Shakespeare addresses the question of whether such knowledge translates to power.  He also explores the various aspects of human nature, including the facets and extents of jealousy (Othello), and appearance versus reality (multiple works), just to name a very few.  As with the themes Shakespeare's incorporates into his works, the list of examples goes on and on.