The Three-year Expedition was an exploratory expedition to East Greenland that lasted from 1931 to 1934 financed by the Carlsberg Foundation and the Danish state. It was led by Lauge Koch. The other participants were Danish and Swedish geographers, geologists, archaeologists, zoologists and botanists: Paul Gelting, Gunnar Seidenfaden, Thorvald Sørensen, Steen Hasselbach, Helge G. Backlund, Gunnar Thorson, Gunnar Säve-Söderbergh, Helge Larsen, Thyge Johansen, L. Bruhn, H. Heinrich Nielsen and N. V. Petersen. The expedition vessels were Godthaab and Gustav Holm. The engagement of the Danish state had political connotations, because of the ongoing dispute between Denmark and Norway over East Greenland.