A league is a unit of length. It was common in Europe and Latin America, but is no longer an official unit in any nation. Derived from an ancient Celtic unit and adopted by the Romans as the leuga, the league became a common unit of measurement throughout western Europe. It may have originally represented, roughly, the distance a person could walk in an hour. Since the Middle Ages, many values have been specified in several countries. Different definitions Ancient Rome The league was used in Ancient Rome, defined as 1½ Roman miles (7,500 Roman feet, modern 2.2 km or 1.4 miles). The origin is the leuga Gallica (also: leuca Callica), the league of Gaul. Argentina The Argentine league (legua) is or 6,666 varas: 1 vara is . England On land, the league is most commonly defined as three miles (4.83 km), though the length of a mile could vary from place to place and depending on the era. At sea, a league is . English usage also included many of the other leagues mentioned below (for example, in discussing the Treaty of Tordesillas). France The French lieue — at different times — existed in several variants, namely 10,000, 12,000, 13,200 and 14,400 French feet, about . It was used along with the metric system for a while, but is long discontinued. A metric lieue was used in France from 1812 to 1840, with 1 metric lieue being exactly 4,000 m, or 4 km (about 2.5 mi). It is this unit that is referenced in both the title and the body text of Jules Verne's novel Twenty Thousand Leagues Under the Seas (1870). Mexico Perhaps in some rural parts of Mexico, the league (Spanish legua) is still used in the original sense of the distance that can be covered on foot in an hour, so that a league along a good road on level ground is a greater distance than a league on a difficult path over rough terrain. Portugal In Portugal, Brazil and other parts of the former Portuguese Empire, there were several units called league (Portuguese: légua): Légua of 18 to a degree = 6,172.84 metres Légua of 20 to a degree (Maritime légua) = 5,555.56 metres Légua of 25 to a degree = 4,444.44 metres The names of the several léguas referred to the number of units that made the length corresponding to an angle degree of