Defender of the Crown puts the player in the role of one of four Saxon knights in medieval England, at a time when the land is in crisis as the King is dead and his crown has been stolen. The Saxons and Normans blame each other and fight for control of England.

After a brief introduction by Robin of Locksley himself, the game begins with a single castle and 10 soldiers at your disposal. From there, you must build your army, take control of additional territories and fight and defeat the three Norman lords and sometimes your Saxon friends as well.

In addition to the basic 'build your army and conquer your opponents', the game offers several events and options that can be used to fine-tune your play style: you can participate in a jousting contest in which you have to knock your opponent off his horse, gaining fame or land, or you can raid a castle in search of loot or the hand of a princess, uniting your houses and territories.