He was born on 8 January 1883 in Tarnów. After graduating in Polish philology from the Jagiellonian University in 1905, he began working at one of Kraków’s gymnasiums. In 1913, he left for Paris to study the history of the Great Emigration. In 1917, he received his habilitation degree, and in 1919, became professor at the University of Warsaw, with which he was associated until the end of his life; he was its rector in 1932/1933. From 1921, he was a member of the Warsaw Scientific Society, and from 1922, of the Polish Academy of Learning. In 1936, he was appointed Deputy Minister at the Ministry of Religious Denominations and Public Education; in the same year, he received the Golden Laurels (Złoty Wawrzyn) medal granted by the Polish Academy of Literature. He died on 8 July 1937 in Warsaw. Ujejski is best known for his Dzieje polskiego mesjanizmu do powstania listopadowego włącznie (The History of Polish Messianism until the November Uprising), published in 1931. In the book, he distinguished three main types of Polish messianism (national, denominational, and class-related messianism), which dated back to as early as the 16th century. His other works: Główne idee w „Anhellim” Słowackiego (The Main Ideas in Słowacki’s Anhelli) (1916), Antoni Malczewski. Poeta i poemat (Antoni Malczewski. The Poet and the Poem) (1921), Byronizm i skotyzm w Konradzie Wallenrodzie (Byron and Scott Influences in Konrad Wallenrod) (1923), O cenę absolutu. Rzecz o Hojne-Wrońskim (The Price of the Absolute. About Hojne-Wroński) (1925), O Konradzie Korzeniowskim (About Joseph Conrad) (1936). A selection of Ujejski’s sketches was published in 1963 in the collection Romantycy (The Romantics).