||The examples and perspective in this article deal primarily with Germany and do not represent a worldwide view of the subject. (December 2010)|
A robber baron or robber knight was an unscrupulous and despotic noble of the medieval period in Europe. The term has slightly different meanings in different countries. In modern U.S. parlance, the term is also used to describe unscrupulous industrialists (see robber baron (industrialist)). Robber baron behavior among the Germanic warrior class in medieval Europe indirectly led to the Catholic innovations of the Peace and Truce of God.
Early development 
For one thousand years, from 800 AD to 1800 AD, tolls were collected from ships sailing on the Rhine River in Europe. During this time, various feudal lords, among them archbishops who held fiefs from the Holy Roman Emperor, collected tolls from passing cargo ships to bolster their finances.
Only the Holy Roman Emperor could authorise the collection of such tolls. Allowing the nobility and Church to collect tolls from the busy traffic on the Rhine seems to have been an attractive alternative to other means of taxation and funding of government functions.
Often iron chains were stretched across the river to prevent passage without paying the toll, and strategic towers were built to facilitate this.
The Holy Roman Emperor and the various noblemen and archbishops who were authorised to levy tolls seem to have worked out an informal way of regulating this process.
Among the decisions involved in managing the collection of tolls on the Rhine were:
- how many toll stations to have,
- where they should be built,
- how high the tolls should be,
- and the advantages/disadvantages.
While this decision process was made no less complex by being informal, common factors included the local power structure (archbishops and nobles being the most likely recipients of a charter to collect tolls), space between toll stations (authorized toll stations seem to have been at least five kilometres apart), and ability to be defended from attack (some castles through which tolls were collected were tactically useful until the French invaded in 1689 and levelled them).
Tolls were standardized either in terms of an amount of silver coin allowed to be charged or an "in-kind" toll of cargo from the ship.
In contrast, the men who came to be known as robber barons (German: Raubritter) violated the structure under which tolls were collected on the Rhine either by charging higher tolls than the standard or by operating without authority from the Holy Roman Emperor altogether.
Writers of the period referred to these practices as "unjust tolls," and not only did the robber barons thereby violate the prerogatives of the Holy Roman Emperor, they also went outside of the society's behavioural norms, since merchants were bound both by law and religious custom to charge a "just price" for their wares.
Interregnum period 
During the period in the history of the Holy Roman Empire known as the Interregnum (1250–1273), when there was no Emperor, the number of tolling stations exploded in the absence of imperial authority. In addition, robber barons began to earn their newly-coined term of opprobrium by robbing ships of their cargoes, stealing entire ships and even kidnapping.
In response to this organized, military lawlessness, the "Rheinischer Bund," or Rhine League was formed by and from the nobility, knights, and lords of the Church, all of whom held large stakes in the restoration of law and order to the Rhine.
Officially launched in 1254, the Rhine League wasted no time putting robber barons out of business by the simple expedient of taking and destroying their castles. In the next three years, four robber barons were targeted and between ten and twelve robber castles destroyed or inactivated.
The Rhine League was not only successful in suppressing illicit collection of tolls and river robbery. On at least one occasion, they intervened to rescue a kidnap victim who had been kidnapped by the Baron of Rietberg.
The procedure pioneered by the Rhine League for dealing with robber barons – to besiege, capture and destroy their castles – survived long after the League self-destructed from political strife over the election of a new Emperor and military reversals against unusually strong robber barons.
When the Interregnum ended, the new Emperor Rudolf of Habsburg applied the lessons learned by the Rhine League to the destruction of the highway robbers at Sooneck, torching their castles and hanging them. While robber barony never entirely ceased, especially during the Hundred Years' War, the excesses of their heyday during the Interregnum never recurred.
British Isles 
The reign of King Stephen of England (1096–1154 AD) was a long period of civil unrest commonly known as "The Anarchy". In the absence of strong central kingship, the nobility of England were a law unto themselves, as characterised in this excerpt from the Anglo-Saxon Chronicle:
When the traitors saw that Stephen was a mild good humoured man who inflicted no punishment, then they committed all manner of horrible crimes. They had done him homage and sworn oaths of fealty to him, but not one of their oaths was kept. They were all forsworn and their oaths broken. For every great man built him castles and held them against the king; they sorely burdened the unhappy people of the country with forced labour on the castles; and when the castles were built they filled them with devils and wicked men. By night and by day they seized those they believed to have any wealth, whether they were men or women; and in order to get their gold or silver, they put them into prison and tortured them with unspeakable tortures, for never were martyrs tortured as they were. They hung them up by the feet and smoked them with foul smoke. They strung them up by the thumbs, or by the head, and hung coats of mail on their feet. They tied knotted cords round their heads and twisted it until it entered the brain. They put them in dungeons wherein were adders and snakes and toads and so destroyed them. Many thousands they starved to death.
United States 
The term robber baron was popularized by U.S. political and economic commentator Matthew Josephson during The Great Depression in a 1934 book. He attributed its first use to an 1880 anti-monopoly pamphlet in which Kansas farmers applied the term to railroad magnates.
See also 
- Matthew Josephson, The Robber Barons: The Great American Capitalists 1861–1901, New York: Harcourt, Brace and Company, 1934.
|Look up robber baron in Wiktionary, the free dictionary.|
- Robber Barons J. Bradford DeLong, University of California at Berkeley, and NBER
- Robber Barons or Captains of Industry? The Great Debate Authored by: Erica Berkshire (2003). University of Oregon.