one of Scandinavia's foremost lyric poets. He was influenced by the French Symbolists (Symbolist movement) and in turn greatly influenced Danish modernist poets of the 1940s and 1960s.

Claussen's family was devoted to farming and politics, and he was intensely interested in the latter. After studying law at Copenhagen, he became a journalist for provincial newspapers, but spent much time in Paris and Italy as a freelance writer and painter.

Claussen sought aesthetic perfection in his light, rhythmical poetry, and with his ingenious symbolism he constantly tried to transform his impressions of the erotic dimension in nature and human life into visionary, religious experiences. Poetry became his gospel. Finding a permanent conflict beween the spiritually erotic and the physically erotic, Claussen strove to unify earthly desire and religious sacrifice in a verbal totality. As reality and illusion come together in his work, the loss of verisimilitude is compensated for in the act of poetic creation, and a new kind of meaning is born that rests entirely within the poem itself. This religious expression, accompanied by a sense of the loss of beauty and the seeming meaninglessness of art in the face of the brutality and materialism of modern life, reached its highest expression in Claussen's last important collection, Heroica (1925). In defiance of his personal sense of isolation, the aging Claussen committed his artistic craft to an unqualified faith in a second coming of life.

In spite of Claussen's close French literary connections, his humorous, romantic play with the myths of human existence in Naturbørn (1887; “Children of Nature”) and Pilefløjter (1899; “Willow Pipes”) remains in the Danish tradition. Claussen also published several travel books and lyrical prose tales of small-town life in Denmark. He translated some of his favourite poets, including Percy Bysshe Shelley (Shelley, Percy Bysshe), Heinrich Heine (Heine, Heinrich), and Charles Baudelaire (Baudelaire, Charles).