"Wrzesień żagwiący" was based on the author's 1943 collection of reportages, published in British Palestine in 1943 during the Mediterranean Campaign. It was titled "Wrześniowym szlakiem". Wańkowicz wrote it under pen name Jerzy Łużyc. In 1947, after coming to London, Wańkowicz expanded "Wrześniowym szlakiem", adding new stories, and changing the name of the publication into "Wrzesień żagwiący". As the author claimed, most of his reportages had been written in the final months of 1939, and were based on personal interviews with soldiers of the Polish Army and Polish civil servants, who witnessed or fought in the Invasion of Poland. Due to his work, the defenders of Westerplatte, and Major Henryk Dobrzański became legendary figures in Polish historiography. Nevertheless, "Wrzesień żagwiący" should not be considered a history books, as in some cases Wańkowicz's interlocutors did not give truthful testimonies. Among others, in August 1946 in Italy, Wańkowicz interviewed Major Henryk Sucharski, who did not mention the fact that in the first days of the Battle of Westerplatte, he suffered a nervous breakdown, and the defence was commanded by Captain Franciszek Dąbrowski.