After proceeding to receive a Master's degree from Lund University in 1950, Hörmander began his graduate studies under Marcel Riesz (who had also been the advisor for Hörmander's gymnasium teacher). He made his first research attempts in classical function theory and harmonic analysis, which "did not amount to much" but were "an excellent preparation for working in the theory of partial differential equations." He turned to partial differential equations when Riesz retired and Lars Gårding who worked actively in that area was appointed professor.