Lars Valerian Ahlfors was a Finnish mathematician and the leading figure in complex analysis during the 20th century. He is remembered for his work on Riemann surfaces, quasiconformal mappings and Teichmüller spaces, and for his textbook on complex analysis. In 1936 Ahlfors was one of the first two recipients of the Fields Medal, along with American mathematician Jesse Douglas, and in 1981 he received the Wolf Prize in Mathematics.