i think it started in the 18th and 19th centuries, there was no real distinction between scientist and philosopher, and many of the great scientist-philosophers of antiquity were also theologians.
Science gave philosophy a way of empirically testing theories and concepts, whilst philosophy has helped to develop the scientific method used today.
Philosophy also dictates what areas science can and cannot test, delineating the boundary between physical and metaphysical questions. These boundaries and the rules governing research have developed over the centuries, and philosophy and science are intertwined.
The history of the philosophy of science shows the development of the underlying methodology and foundations of the scientific process, and shaped science.