Convert from mille [French] to league [ancient Celtic]

Unit Definition (mille [French])
The mille is a traditional French mile, equal to 1000 toises. This is equal to about 6394.4 feet, 1.211 statute mile, or 1949 meters. In modern France, the mille sometimes means the nautical mile (mille marin), equal to exactly 1852 meters.

Unit Definition (league [ancient Celtic])
League is a unit of distance long common in Europe and Latin America, although no longer an official unit in any nation.