Background
He was born in Kurla Pilistvere Parish, Kreis Fellin, Governorate of Livonia (now Türi Parish, Järva County).
He was born in Kurla Pilistvere Parish, Kreis Fellin, Governorate of Livonia (now Türi Parish, Järva County).
Rei studied in the Tartu Emperor Alexander High School (the former State High School of the Livonian Governorate), but graduated from the Novgorod State High School. In 1904–1905 and 1907–1911, studied law in the Saint St. Petersburg University.
In 1905–1907, Rei participated in the Russian revolution of 1905. In 1906, he edited the underground paper Sotsiaaldemokraat (Social Democrat) in Tallinn. Between 1912 and 1913, he was in compulsory army service.
In 1913–1914 he worked as a lawyer in Viljandi.
In 1914 – 1917 Rei was an artillery officer in World War I at the Fort of Saint St. Petersburg. He was the Assistant Chairman of the Supreme Committee of the Estonian military.
In 1917 and 1919, he was the Editor-in-Chief of the paper Sotsiaaldemokraat. Between 1927 and 1928 he was the editor of Rahva Sõna (Word of the People).
Rei was one of the leaders of the moderate faction of Estonia"s social democratic movement.
He received an Honorary Doctorate in Law from Tartu University. Minister of Labour and Social Welfare of the Provisional Government. Deputy Prime Minister.
Acting Minister of: 1918–1919
Chairman of the Constituent Assembly (Asutav Kogu): 1919–1920
Head of the Estonian Delegation to the Estonian-Latvian Border Committee: 1923–1925
Speaker of the II Riigikogu.
1925–1926
State Elder (Head of State): 4 December 1928 – 9 July 1929
Minister of Foreign Affairs: 1932–1933
Deputy Minister of Foreign Affairs: 1936–1937
Envoy to the Soviet Union: 1938–1940
Minister of Foreign Affairs in exile: 1944–1945
Prime Minister in capacity of the President of the Republic in exile: 9 January 1945 – 29 March 1963.
Rei wrote and translated socialist works and published memoirs.
Up to 1936 he also worked as a lawyer and defended Ado Birk in 1927.
Member of the Estonian Provincial Assembly (Maapäev): 1917–1919.