In 1896 a professorship of zoology was established for him at the Christiania university; he worked up the results of his expedition and made scientific research in physical geography and oceanography. In the summer of 1900 he took part in an Arctic oceanographic expedition in the S.S. "Michael Sars," headed by Dr. Johan Hjort, and became director of the Inter national Central Laboratory in Christiania for the 4esearch of the Sea. In 1902 he published The Oceanography of the North Polar Basin, and in 1904 The Bathymetrical Features of the North Polar Seas. In 1905 Nansen took up politics, issuing a manifesto and many articles in connection with the crisis between Norway and Sweden. His attitude may be summarized by the last words of a short work published later in the year : "Any union in which the one people is restrained in exercising its free dom is and will remain a danger" (Norway and the Union with Sweden, London, 1905). On the establishment of the Norwegian monarchy Nansen was appointed minister to England (1906), and in the same year was created G.C.V.O. In 1908 he retired from his post and returned to his scientific work as professor of ocean ography at Christiania university. In co-operation with Pro fessor Bjorn Helland-Hansen, of the Bergen Museum, he wrote The Norwegian Sea, its Physical Oceanography (Report on Nor wegian Fishery and Marine Investigations, vol. 2, 1909).
In 1910 Nansen made an oceanographic cruise in the "Frith jof" through the northeastern North Atlantic from Ireland to Iceland and back to Norway, and in 1911 published In Northern Mists (2 vol.) on the exploration of the northern regions from early times up to the beginning of the 16th century. In 1912 he made a further oceanographic cruise to Spitsbergen and the waters to the north in his yacht the "Veslemoy," and in 1913 he made an expedition through the Arctic and the Kama Seas to the mouth of the Yenisei river and through Siberia and the Amur region.
In 1914, jointly with Helland-Hansen, Nansen made an oceano graphic expedition in the eastern North Atlantic to Portugal, Madeira and the Azores and back to Norway. During the World War oceanographic expeditions were impossible. In 1917 Nansen became head of a Norwegian Govt. commission to the United States, and secured a satisfactory agreement with the American Govt. in regard to the import into Norway of essential supplies. After the Armistice (1918) Nansen, as Commissioner of the League of Nations with the executive assistance of the national Red Crosses, was responsible for the repatriation of about 500,000 prisoners of war from Siberia, China and other parts of the world. This work was financed largely by the governments par ticipating in the International Committee for Relief Credits, Paris, of which Lord Bradbury was chairman.
In 1919 Nansen conferred with Hoover on the possibilities of assisting the Russian people, and suggested an organization on the lines of the Belgian Relief Commission. The Supreme Coun cil supported the proposal on the condition that all hostilities in Russia cease. As this was at the time when Kolchak and Denikin were advancing towards Moscow the project was abandoned. In
1921 Nansen was asked by an international conference in Geneva of delegates of 48 Red Cross societies and 12 governments to direct relief work for famine-stricken Russia, and on Aug. 27 he signed an agreement in Moscow with Chicherin, the Soviet Foreign Minister, regarding the method of furnishing relief on a large scale, and visited the famine areas. In Sept. Nansen failed to induce the League of Nations to assist the starving millions in Russia by raising, under safeguards, an international governmental relief loan. He next visited the chief capitals of Europe, and as a result the European Red Crosses fed and clothed at the peak of the Russian famine over 1,600,000 inhabit ants of the Volga and South Ukraine regions. His publicity cam paign had great influence in America, which under Hoover's di rection fed at one time 1 o,000,000 Russian sufferers. Nansen's mission in Russia continued to conduct two agricultural demon stration estates in the former famine areas. In 1923 Nansen published Russia and the Peace setting out the economic position of Soviet Russia. As high commissioner for refugees to the League, he was responsible for the protection and settlement of Russian, Armenian and Greek refugees.
Besides works mentioned above, Nansen described his travels in The First Crossing of Greenland (Eng. trans., 1893) ; Farthest North (Eng. trans., 1897) ; The Waters of the Northeastern North Atlantic (Inter nationale Revue der gesammten Hydrobiologie and Hydrogeographie, Leipzig, 1913) ; En fend til Spitzbergen (1912) ; Through Siberia, the Land of the Future (London, 1914). The scientific results of the vari ous expeditions are given in the following works—the 1888 expedition, in Petermanns Mitteilungen (Gotha, 1892) ; the 1893 expedition, in The Norwegian North Pplar Expedition, 1893-96: Scientific Results (Lon don, etc., 190o sqq.) ; the 1912 expedition, in Spitzbergen Waters (Society of Science, Oslo, 1915) ; of the 1914 expedition jointly with Helland-Hansen, in The Eastern North Atlantic (Geophysic Publica tion, Academy of Science, Oslo).