Walid Khalidi was a Palestinian historian who wrote extensively on the Palestinian exodus. He co-founded the Institute for Palestine Studies (IPS) in Beirut in December 1963 as an independent research and publishing center focusing on the Palestine problem and the Arab–Israeli conflict, and was its general secretary until 2016. Khalidi's first teaching post was at Oxford, a position he resigned from in 1956 in protest at the British invasion of Suez. He was Professor of Political Studies at the American University of Beirut until 1982 and thereafter a research fellow at the Harvard Center for International Affairs. He also taught at Princeton University.