Paul D'ianno

he was kicked out for having a pretty bad cocaine problem. it was starting to have a bad effect on his performances and steve and rod smallwood realised he wouldnt stand up to a full on world tour (think what would have happened if he had been on the 'world slavery tour'?).
he kinda had doubts about his future with maiden at the same time though. he knew himself that he would find it hard to cope with the huge world tours that steve had planned. it wasnt really mutual, but both sides could see it made sense.

he's still on good terms with the band though. there are some interviews with him on the 'early days' dvd i think.