In 17th century, the King of which country planned to create a moose cavalry but failed?

Moose cavalry are military units of cavalrymen mounted on moose (AKA Eurasian elk, Alces alces alces) rather than the more usual horses. There are legends that state that the Mansi people of Western Siberia rode moose into battle but there is no evidence of this.

In 17th-century Sweden Charles XI trialled the use of moose as a replacement for horses, which had to be imported. However they proved susceptible to disease, hard to feed and fearful of the sound of gunfire. The use of moose cavalry by the Soviets in the Winter War of 1939 and 1940 is also reported but seems to stem from a 2010 Popular Mechanics April Fools' Day article.