Tillyard had great influence on criticism of Richard II. He explained the play with Elizabethan political doctrine which regards a nation as a part of divine order. This kind of criticism, however, was challenged by other critics because it oversimplified the play’s complexity and its meanings. Richard II is a history play with abundant political ambiguity because of which its meaning cannot be simplified. This paper focused on political notions of divine right of kings, justification of deposition, and Essex rebellion with historical background which could be clues in our understanding about ambiguous political moments permeated in the play. The political and religious doctrine of divine right of kings is already unstable from the beginning of the play. It can not protect the legitimate king from usurpation any more, and law seems more effective to be a king. Even the religious leader who supports this divine right is aware of realpolitk. Richard’s moral faults and political inability suggested to justify his deposition are ambiguous because they are rather applied to the usurper Bolingbroke and his rebellion party. During the Queen Elizabeth rein, Richard was often compared to Elizabeth in many political aspects, especially, of her wrong doings, and it made the story of Richard II politically sensitive to the government. Thus, the fact that Richard II was played by request of Essex supporters on the previous day of the rebellion was not meaningless. However, their rebellion failed, and it seemed they ignored the ambiguous meaning of this play and see only what they wanted to see in it, that is a successful usurpation. Shakespeare does not take politics as God’s will. For him, it is a process of cause and effect of human actions. It is very clear in the two parts of Henry IV in which rebellions against usurper Bolingbroke continue restlessly until his death. Richard II is a tragedy of ambition and Shakespeare shows his shrewd understanding on human nature very cleary with political ambiguity in this play.