Why did Carl Gustaf Verner von Heidenstam win The Nobel Prize in Literature 1916?

Verner von Heidenstam did not win the Nobel Prize in Literature in 1916. That year the prize was awarded to Verner von Heidenstam's fellow countryman, Carl Gustaf Verner von Heidenstam. His motivation was "in recognition of his significance as the leading representative of a new era in our literature".