From 2014 we commemorate the 100th anniversary of WWI all over the world. It's understandable that the topic is highlighted by special surveys. An important part of it is the search for private papers. In modern history writing the sources mirroring individual views, the documents that do not form politics but give back experiences of people living ordinary life come to the front. Such are the wartime diaries and memoirs from the time of WWI, fortunately remaining in substantial numbers. These provide special searching possibilities for researchers. Several cultural, mentality, civilization and strategical historical data can be revealed with the help of them, as they are excellent sources regarding relations between nations living side by side or waging war against each other. The most important thing is that through them we can know individual stories, processions of intense experiences, thoughts of ordinary people. So such levels of historical past that cannot be revealed by studying great politics, only by smaller surveys. With the help of it we can compare official wartime propaganda to a soldier's experience on the front line. What did it mean in reality for him that the official papers coded as heroic war for God, home, nation, king etc.? I propose to prove the special historical value of such sources with the help of several wartime diaries and memoirs.