Bristol Siddeley Engines was a British aerospace company known for manufacturing aircraft engines. Established in 1956, it emerged from the merger of Bristol Aeroplane Company and Siddeley Engines. The company played a significant role in the development of jet engines for both military and civilian aircraft. In 1960, Bristol Siddeley became part of Rolls-Royce, further enhancing its capabilities in engine design and production. The company is recognized for notable engines like the Orpheus and Bristol Proteus, which contributed to advancements in aviation technology during the mid-20th century.