The article aims to characterize a topical issue through poetics: the Second World War from the perspective of J. Iwaszkiewicz’s individual perception from September 2, 1939, when the Luftwaffe began to bomb Warsaw until the moment of its liberation on January 18, 1945. It is noted that the writer recorded on the pages of his diary not only his psychological state but also that of other people. Particular attention is paid to the first entry of August 12, 1939, where the breakdown of the peaceful life was recorded, during which the writer had been immersed in the problems of art, intending to create a free-form work, a kind of ANNABEL, where the images of the composer Karol Szymanowski, the poets J. Tuwim and S. Witkiewicz would have appeared. The article focuses on the entry of August 28, 1939, which tells about the writer’s deep love for Ukraine and his nostalgic memories of it. The study emphasizes the historical value of almost daily records dedicated to mobilization, dated August 24 and 31, and those testimonies contained in the diary entries from September 4, 5 and 6, which describe the terrible pictures of people fleeing from Podkowa and the state of the road to it, destroyed by bombing. The entry about a terrible entrance to Warsaw, dated September 7, and that with a group portrait of crowds on the roads, dated September 8, are considered from the point of view of artistic skill. The article studies the poetics of tragic scenes of Warsaw residents’ escape and analyzes the entries depicting the underground cultural life of the capital, the secret academy dedicated to K. Szymanowski’s death anniversary, the series of J. Iwaszkiewicz’s lectures about contemporary Polish poetry, Stawisko, where the writer hid writers, artists and fighters against the invaders, about the Uprising and post-war reconstruction. Attention is also given to the recollection of K. Baczynski and W. Draczynska’s marriage.