Complex sentence: The New Romantic scene had developed in the London nightclubs Billy's and the Blitz in the late 1970s and was characterised by club-goers wearing flamboyant, eccentric costumes and make-up derived from the historical Romantic era.
Split into simpler sentences: The New Romantic scene developed in the London nightclubs Billy's and the Blitz in the late 1970s. Club-goers wore flamboyant, eccentric costumes and make-up derived from the historical Romantic era.