Complex sentence: The group instead chose to remain independent, and became the Sheffield Socialist Society.In order to promote the socialist cause in Sheffield he wrote'England Arise!, a marching song, rivalling Connell's'Red Flag' in the British Labour Movement.
Split into simpler sentences: The group instead chose to remain independent, and became the Sheffield Socialist Society. Also while in Sheffield he wrote'England Arise!, a socialist marching song to promote left-wing politics, rivalling Connell's'Red Flag' in the British Labour Movement.