I've learned something from this thread that may help me in Trivial Pursuit!

After Denmark–Norway was attacked by Britain, it entered into an alliance with Napoleon , and in 1814 found itself on the losing side in the Napoleonic Wars and in dire conditions and mass starvation in 1812. The Dano-Norwegian Oldenburg king was forced to cede Norway to the king of Sweden. Norway took this opportunity to declare independence, adopted a constitution based on American and French models , and elected the Danish crown prince Christian Fredrik as king on May 17, 1814. However, Sweden militarily forced Norway into a personal union with Sweden , establishing the Bernadotte dynasty as rulers of Norway. Under this arrangement, Norway kept its liberal constitution and independent institutions, except for the foreign service.

A Personal Union is something akin to Canada's recognition of the british monarchy (I think...)