Names are a very, very, very big deal in Richard II. Remember when Henry Bolingbroke, Duke of Hereford, returns to England to claim the land he was supposed to inherit when his dad (Gaunt/Lancaster) died? Henry makes a huge deal out of the fact that he wants to be called "Lancaster" now, not "Hereford," because the Dukedom of Lancaster is his rightful inheritance and King Richard has taken it from him illegally. (Remember, members of the nobility are named after the land they control.) Check it out:
My Lord of Hereford, my message is to you.
My lord, my answer is – to Lancaster;
And I am come to seek that name in England;
And I must find that title in your tongue,
Before I make reply to aught you say. (2.3.1)
In other words, Henry wants to be called Lancaster because he wants Richard to acknowledge that he has a right to inherit his father's land. Remember, if you haven't inherited property from your ancestors, then you're not a nobleman – you're a "man of no name" (a.k.a. a commoner and a nobody). More than in any other history play, characters in Richard II tend to derive their identities from their names.