Complex sentence: Formby began to develop his own stage act during the 1890s, building a large following in Lancashire as he did so, and devised several characters with their own costumes, and a series of comic songs.
Split into simpler sentences: Formby began to develop his own stage act during the 1890s, building a large following in Lancashire as he did so. He devised several characters with their own costumes, and a series of comic songs.