Convert from pied de roi to league [UK]

Unit Definition (pied de roi)
The pied is a traditional French foot. Pieds of various lengths were used in France, but the one best remembered now is the royal foot (pied de roi), called the Paris foot in English and the foot (French measure) in Canadian law. The pied de roi equals about 32.48 centimeters or 12.79 inches; the official Canadian definition is 12.789 inches (32.484 06 centimeters). Today the word pied is sometimes used informally in France as a metric unit equal to 30 centimeters. In French Canada, pied is generally used to refer to the English foot.

Unit Definition (league [UK])
The league became a common unit of measurement throughout western Europe, although its length varied greatly from region to region. It was originally intended to represent the distance a person could walk in an hour. In many cases it was equal to 3 miles, (note that the definition of a mile also varied from region to region). At sea, the league was often equal to 3 nautical miles, which is 1/20 degree or 5556 meters (metres). In the USA and Great Britain, the league is defined to be 3 statute miles on land, or 3 nautical miles at sea.