Danish painter and designer, born in Copenhagen, where he studied at the Royal Academy, 1931–2. While still a student he discovered the work of Kandinsky and during the 1930s he played an important role in introducing abstraction to Denmark, being one of the founders in 1934 of the group Linien (The Line), a small circle of abstract artists; it published a periodical of the same name. In 1947 Mortensen settled in Paris, but he returned to Copenhagen to become a professor at the Academy in 1964, holding this post until 1980. During the Second World War Mortensen painted some harsh, tormented canvases, but his most characteristic pictures are sophisticated in composition and refined in colour; they feature smooth, taut sheets of colour interlocking with sharp lines, creating a subtle interplay between surface tension and spatial allusion and combining clear articulation with a lively feeling of spontaneity. He also produced tapestry cartoons and designs for theatrical sets and costumes.
From A Dictionary of Modern and Contemporary Art in Oxford Reference.