The son of Tomáš Masaryk, he helped in establishing the Czech republic and thereafter was mainly involved in foreign affairs. As ambassador to Britain (1925–38), he resigned in protest at his country’s betrayal under the Munich Pact (1938). On the liberation of Czechoslovakia by the Allies (1945) he became Foreign Minister, and was dismayed at the Soviet veto of Czechoslovak acceptance of US aid under the Marshall Plan. At the request of President Beneš, he remained in his post after the communist coup of February 1948, but he either committed suicide or was murdered three weeks later.