Machiavelli would have a lot to say about King Richard. So many of the things that Machiavelli wrote about in The Prince, can apply to both men. 

First we will start with Richard. Richard thinks that God has specifically chosen him to be king. He thinks that because of this, he has nothing to be afraid of, when Henry invades England. He banishes his own cousin, Henry Bolingbroke, and covers up the murder of his uncle. He starts to rent some of the royal land and takes another of his uncles land. This uncle is the father of Henry, so be taking the land, Richard has deprived Henry of his birthright. Many of his previous supporters and the commoners think he has finally gone too far. He squanders the money he has. He has lost the respect of the people. This is a very dangerous place for a king to be.

Bolingbroke on the other hand would be more the Machiavelli's liking. Machiavelli gives a list of what a powerful leader should have. Bolingborke has them in spades. First of all he is inventive and opportunistic. When Richard is away in Ireland, Bolingbroke sees this as the perfect time to come back to England and reclaim his birthright. He is very charismatic because he is great at getting people to join his side. Commoners love him and the noblemen joins his forces. Richard is even aware of this. Bolingbroke is willful. While he is in France he gathers a giant army and heads to England and finally corners Richard at Flint Castle. He is ruthless to some degree. He has Richard imprisoned and eventually killed, but he shows mercy on some of the people who supported Richard as well. He even feels guilt over the death of Richard. 

Richard failed to meet some of Machiavelli's idea of a good leader. Machiavelli believed that a good leader must avoid the hatred of his people. He thought they should be feared rather than loved. He also warns about doing things that would make people turn against him, such as confiscating property and land and the dissolution of traditional institutions. Richard went against all of these. Richard failed to have the people fear him and he lost their respect, by taking their properties and not caring about the good of his kingdom.