Complex sentence: Its creation was inspired by the European performance of 1982--83, and reach over five thousand members in the following years, but in the early nineties, a disagreement resulted in the creation of another Benfica's supporters group No Name Boys.
Split into simpler sentences: Its creation was inspired by the European performance of 1982--83. They reached over five thousand members in the following years, but in the early nineties, a disagreement resulted in the creation of another Benfica's supporters group No Name Boys.