Definition: Generate a correct and concise answer for the question based on the words in the context.
Input: Context : Robert Martinek (2 February 1889 -- 28 June 1944) was an artillery officer in the Austro-Hungarian Army during World War I, the Austrian Bundesheer and, during World War II, in the Wehrmacht Heer, who came to be regarded as one of the most skilled artillerymen of his generation. 
Question : What war or battle did Robert Martinek fight in?
Output:
World War I