This book provides a detailed listing and description of over four years of continuous fighting in the air in World War I, by assembling the 7500 casualties that the British and Commonwealth, and American air services suffered. Every single day of the war has been examined and the circumstances checked from every available source. Both Allied and Axis sources have been studied, resulting in thousands of cross-links with, confirmations of and changes to our previous knowledge of the subject. The book is chronological in structure and the exhaustive listings are linked by contextual passages and commentary. Moreover, every single combat and casualty for the first 18 months of the war has been tracked down, providing a completly new and detailed picture of the air battle for 1914 and 1915.