Instructions: Generate a correct and concise answer for the question based on the words in the context.
Input: Context : Hans-Georg von Seidel (11 November 1891 -- 10 November 1955) was a German military leader who served in the German Army during World War I and in the Luftwaffe (German Air Force) during World War II. Seidel was promoted to the rank of General der Flieger (General of the Air).
Question : In which war did Hans-Georg von Seidel participate?
Output:
World War I