Classic mini wont start, car help?

Yesterday i tried to start my classic mini and it was turning over but not starting what so ever, only a little noise like it was starting when the key turned back but it didnt start. i charged the battery overnight and put it back in today, i tried to start it and noticed that the interior lights and exterior lights had stopped working all but 2. so i assume thats an alternator problem? But i thought the car should start without an alternator? please help... its a 1992 mini city thanks in advance
no... i noticed that the lights are slowly dying one by one, which is a sign of a broken alternator