V pushed D against a wall and slapped her, so she hit him with a glass (not realising that she was holding the glass). Judge said that self-defence was not open to an assailant: only the attacked party. To be the attacked party it was necessary to prove that one had tried to disengage or demonstrate unwillingness to fight. She was convicted. CA allowed her appeal. They said that unwillingness to fight or attempts to withdraw etc were merely evidence of being the attacked party, rather than the attacker, and there were other ways this could be proved. Lord lane says the duty to retreat no longer exists and therefore, while retreat may provide evidence of D’s situation, it is not necessary.