 The outbreak of war led to problems although Ahlfors was unfit for military service.He was offered a post at the Swiss Federal Institute of Technology at Zurich in 1944 and finally managed to travel there in March 1945.He did not enjoy his time in Switzerland, so in 1946 he jumped at a chance to leave, returning to work at Harvard where he remained until he retired in 1977; he was William Caspar Graustein Professor of Mathematics from 1964.