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League (unit)

League (unit) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand League (unit) rather than just read about it. In short: A league is a unit of length. It was common in Europe and Latin America, but due to its highly inconsistent definition, it is no longer an official unit in any nation.

League (unit) — main illustration
League (unit) — illustration

Key takeaways

  • League (unit) belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect League (unit) to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of League (unit) from memory before moving on to harder problems.

Reference excerpt

A league is a unit of length. It was common in Europe and Latin America, but due to its highly inconsistent definition, it 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. Since the Middle Ages, values varied between countries, ranging from 2.2 to 7.9 km (1.4 to 4.9 mi). It may have originally represented, roughly, the distance a person could walk in an hour.

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 5.572 km (3.462 mi) or 6,666 varas: 1 vara is 0.83 m (33 in).

England

On land, the league is most commonly defined as three miles (4.83 km), although the length of a mile could vary from place to place as well as depending on the era. At sea, a league is three nmi (3.452 mi; 5.556 km). English usage also included many of the other leagues mentioned below (for example, in discussing the Treaty of Tordesillas). The Battle Abbey Chronicles define a leuga (league) as the English leuga. This contains 12 roods, and 40 perches make a rood. The perch is 16 feet in length, so by this definition a league is 7,680 feet.

France

The French lieue—at different times—existed in several variants, namely 10,000, 12,000, 13,200 and 14,400 French feet, about 3.25 to 4.68 km (2.02 to 2.91 mi). It was used along with the metric system for a while, then discontinued. A metric lieue was used in France from 1812 to 1840, with 1 metric lieue being exactly 4,000 metres (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 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 a meridian arc. For compatibility after Portugal adopted the metric system, the metric légua of 5.0 km was used. In Brazil, the léguas is still used occasionally, where it has been described as about 6.6 km.

Spain

The legal Spanish legua was originally understood as equivalent to 3 millas (Spanish miles). This varied depending on local standards for the pie (Spanish foot) and on the precision of measurement, but was officially equivalent to 4,180 metres (2.6 miles) before it was abolished by Philip II in 1568. Since 1568, the common league of 5,572.7 metres has been used. It remains in use in parts of Latin America, where its exact meaning varies.

Legua náutica (nautical league): Between 1400 and 1600 the Spanish nautical league was equal to four Roman miles of 4,842 feet, making it 19,368 feet (5,903 metres or 3.1876 modern nautical miles). However, the accepted number of Spanish nautical leagues to a degree varied between 14 1/6 to 16 2/3, so in actual practice the length of a Spanish nautical league was 25,733 feet (4.235 modern nautical miles) to 21,874 feet (3.600 modern nautical miles) respectively. Legua de por grado (league of the degree): From the 15th century through the early 17th century, the Spanish league of the degree was based on four Arabic miles. Although most contemporary accounts used an Arabic mile of 6,444 feet (1,964 metres), which gave a Spanish league of the degree of 25,776 feet (7,857 metres or 4.242 modern nautical miles) others defined an Arabic mile as just 6,000 feet making a Spanish league of the degree 24,000 feet (or 7,315 metres, almost exactly 3.95 modern nautical miles). Legua geographica or geográfica (geographical league): Starting around 1630 the Spanish geographical league was used as the official nautical measurement and continued so through the 1840s. Its use on Spanish charts did not become mandatory until 1718. It was four millias (miles) in length. From 1630 to 1718 a millia was 5,564 feet (1,696 metres), making a geographical league of four millias equal 22,256 feet (6,784 m or 3.663 modern nautical miles). But from 1718 through the 1830s the millia was defined as the equivalent of just over 5,210 feet, giving a shorter geographical league of just over 20,842 feet (6,353 m or 3.430 modern nautical miles). Legua marítima (maritime league): From around 1840 through the early 20th century, a Spanish marine league equaled 18,263.52 feet (5,566.72 metres or 3.00579 modern nautical miles). In the early Hispanic settlements of New Mexico, Texas, California, and Colorado, a league was also a unit of area, defined as 25 million square varas or about 4,428.4 acres. This usage of league is referenced frequently in the Texas Constitution. So defined, a league of land would encompass a square that is one Spanish league on each side.

Comparison table A comparison of the different lengths for a "league", in different countries and at different times in history, is given in the table below. Miles are also included in this list because of the linkage between the two units.

Similar units:

1,066.8 metres – verst, see also Obsolete Russian units of measurement 3,200 metres – kosh, used in North Bihar, India.

See also Medieval weights and measures for various definitions of the league. List of obsolete units of measurement Portuguese customary units Spanish customary units Seven-league boots Walking Parasang

References

Worked examples

Example 1 — a first encounter with League (unit)

Start with the simplest possible case. Write down what League (unit) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to League (unit) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about League (unit) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of League (unit)

In research
League (unit) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses League (unit) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
League (unit) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Customary units of measurement in the United States, Human-based units of measurement, Imperial units, so understanding it makes those chapters shorter.
In everyday life
Look for League (unit) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study League (unit) in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what League (unit) means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain League (unit) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is League (unit) in simple terms?

A league is a unit of length. It was common in Europe and Latin America, but due to its highly inconsistent definition, it is no longer an official unit in any nation.

Why does League (unit) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study League (unit)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on League (unit).

Tags

  • Customary units of measurement in the United States
  • Human-based units of measurement
  • Imperial units
  • Obsolete units of measurement
  • Units of length

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