Note: Australia is generally considered to be a continental landmass, rather than an island. If however one does count Australia among the islands it, not Greenland, would be the largest in the world (unless one also considered Antarctica an island).
... 1905 the southern part of the island below 50° N was ceded to Japan, the Russians retaining the other three-fifths of the area. In August 1945, Russia again took over the ...