Was RR not the pioneer of the large bypass.
No, they were not. GE developed the high bypass engine and concept and patented it. It became the basis for the TF39 engine for the C-5 Galaxy military transport. The first commercial high bypass engine was developed by Pratt & Whitney. It was the JT9D for the Boeing 747. Rolls Royce (RB-211) and GE (CF6-6) engines followed in the commercial marketplace.