In which year was the RAF established?

The Royal Air Force (RAF) was established in 1918, making it the world's first independent air force. It was formed on April 1, 1918, during World War I, as a result of the merger of the Royal Flying Corps and the Royal Naval Air Service. This establishment was crucial in recognizing the importance of air power in military operations, and it laid the foundation for the development of air strategy in modern warfare. The creation of the RAF marked a significant step forward in air combat capabilities and represented a pivotal moment in military history.

The other years listed do not correspond with the establishment of the RAF; 1914 was still in the early stages of World War I, while 1939 marked the beginning of World War II, and 1945 was the year the war ended. Therefore, 1918 is correctly identified as the year the RAF was officially established.