The article analyses the ways in which the Russian philosopher Nikolai Berdiaev understood Russian space and geography, beginning with the texts that he wrote during the First World War and ending with his book The Russian Idea (1946) The claim that some kind of correspondence exists between a specific Russian mentality (or the "Russian soul") and the vast and wide-open Russian landscape, has been described as "one of the most popular Russian autostereotypes" (Møller 1999, 11). One of the most prominent proponents of this stereotype in the first half of the Twentieth Century was the Russian philosopher Nikolai Berdiaev . Berdiaev would return to this connection time and time again in his writings on Russia and Russian thought.Berdiaev published his first book in 1901. In time Russia itself would become a central topic in his philosophical writings. Berdiaev's interest in Russia peaked for the first time during the First World War. Simultaneously with the writing of what is considered his major philosophical work, The Meaning of Creativity (1916), Berdiaev began to produce a vast output of smaller pieces on Russia. It was the war itself that prompted Berdiaev to reflect upon Russia, but his pieces were concerned not so much with the ongoing war as with Russia's history, culture and people, which he often approached from a religious, messianic-prophetic perspective. Before the war he had disseminated his views on Russia and its meaning from time to time, for instance in The Philosophy of Freedom (1911) or in his 1912 monograph on the Slavophile Aleksei Khomiakov, in which he suggested that a messianic self-awareness was something distinctively Russian. However, it was during the war that "this messianism reached its most optimistic and triumphalist peak" (Siljak 2016, 749).