Eric the Red visited Greenland in 982 when it was still green, and four years later people decided to live there full time. Denmark took Greenland under its wing in 1261.
Over the next 140 years or so, Greenland turned mostly white, and by around 1400 it was too cold for even the cows, so everybody left.
Over 300 years later, in 1721, Denmark came back for another try. After two hundred years they were successful enough to claim the whole island. Greenland became autonomous in 1979. Greenland was the only known source of natural cryolite on the planet, but it ran out.
Greenland on Wikipedia