During the Renaissance, English literature gained greater psychological complexity. The Middle Ages was largely dominated by plays more interested in imparting morals or presenting religious stories than anything else. Around the fifteenth and sixteenth centuries, humanism—a system more interested in human affairs than what might occur after death—was on the rise.
Poetry flourished during this period. English poets were inspired by Italian poetry in particular. Edmund Spenser sought to write his own national epic in The Faerie Queene, a work as Protestant as Dante Alighieri's The Divine Comedy is Catholic. Shakespeare penned his famous collection of sonnets during this period as well.
English drama of this period was heavily influenced by the theatre of the ancient Greeks and Romans, a trend followed by science, visual arts, and philosophy, which also took cues from antiquity during the Renaissance. The Roman playwright Seneca was a big influence on English tragedies, particularly "revenge tragedies" such as The Spanish Tragedy or Hamlet. These plays tended to have their characters brought low not by bad fortune or supernatural temptations, but through bad decisions or fatal flaws already present within the hearts of the characters, much as the tragedians of antiquity did. Comedies used similar situations and character types as the Greek/Roman farces as well.
A play like Hamlet is a perfect example of how the Renaissance affected English literature: a medieval version of this story might have rendered Hamlet's inner turmoil as mere good versus evil, while, as it is, the play is psychologically complicated and more ambiguous regarding the morality of its cast of characters, many of whom do not fit into simple "bad" or "good" categories.