Dating back to the feudal period of medieval Europe, the derogatory term "robber baron" was applied to some of America's most notorious industrialists and financiers during the late 19th century.

Widely regarded as ruthless, unscrupulous, and entirely consumed by insatiable greed, these mercenary individuals were the original "fat cats," engaging in everything from shameless bribery and corruption to worker exploitation and manipulation of the stock market.

Read on to discover the 10 most notable examples, including a few who have perhaps been unfairly labeled with the term...

All dollar amounts in US dollars

The medieval-born phrase robber baron was a nod to the "Raubritter" ("robber knights"), powerful German lords who ripped off travelers passing through their lands by levying illegal tolls.

The first mention of the term in the US was in an 1859 New York Times piece that critiqued the industrialist Cornelius Vanderbilt.

Born in New York in 1794, the insatiable Vanderbilt would become the patriarch of one of America's most storied dynasties. His was a true rags-to-riches tale after he was born into poverty and began his working career alongside his illiterate seaman father.

In 1810, at the age of 16, Vanderbilt decided to launch a ferry service. He borrowed funds to buy his first boat and was given the seafaring nickname "the Commodore," which would follow him for the rest of his life.

After a long stint working for a steamship operator – during which he honed his savage business skills – the cut-throat entrepreneur established a steamship line of his own. He swiftly cornered much of the market by undercutting competitors and manipulating stock prices before ruthlessly buying out his weakened rivals.

The Commodore used similar tactics when he moved into the railroad industry during the 1860s, famously sparring with fellow robber barons Jay Gould, James Fisk, and Daniel Drew.

Thanks to his uncompromising approach, Vanderbilt amassed a net worth equivalent to more than $200 billion in today's money. However, unlike numerous industrialists of the day, he gave little of his enormous fortune to those in need. His only significant donation on record was a million-dollar endowment to build the university that bears his name.

As robber barons go, Jay Gould was hands-down the worst of the worst.

A man of minimal morals, Gould was born in 1836 and, much like Vanderbilt, was entirely self-made. He started a survey business at the age of 16 and had made enough money to set up a leather tannery by the time he was 20.

After relocating to New York City in the 1850s, he began speculating on the stock market, bribing politicians and judges so he could get away with his many unethical financial practices.

Early on in his career, Gould is said to have drawn his partner in the tannery business into engaging in reckless speculation, resulting in the poor man's financial ruin and subsequent suicide. Gould, however, prospered. Specializing in railroad stock, he was also on the board of several rail-related companies, including the Erie Railroad.

This put him at loggerheads with Cornelius Vanderbilt, who attempted to take over the business in the late 1860s. Together with James Fisk and Daniel Drew, Gould paid off officials and issued fraudulent stock, eventually fending off Vanderbilt and gaining control of the company.

The following year, the unprincipled tycoon teamed up with Fisk to corner the gold market. (Cornering is the process of buying up a large amount of a commodity or a high number of shares in an attempt to manipulate an asset's price.) This led to the Black Friday financial panic of 1869.

Thereafter, Gould turned his attention to railroads in the West, as well as the telegraph industry. Arguably arrogant and snobbish, he famously once boasted that he could "hire one half of the working class to kill the other half." His desire to get what he wanted knew no bounds, and he even once hatched a plan to kidnap the self-styled Lord Gordon Gordon, who'd swindled Gould out of a railroad-related fortune.

Crooked till the bitter end, Gould died in 1892 at the age of 56, leaving behind a fortune equivalent to $2.4 billion in today's money.

Dubbed the "Barnum of Wall Street," James Fisk was born in 1834 and had a colorful early career that saw him work variously as a circus hand, waiter, and dry-goods salesman before he entered the stock market.

In 1866, he established a brokerage firm with the assistance of his mentor, Daniel Drew. The pair conspired with Jay Gould to prevent Cornelius Vanderbilt from taking over the Erie Railroad.

Alongside Drew and Gould, Fisk bribed officials and issued fake shares in a bid to water down Vanderbilt's stake in the railroad.

Fisk then joined Gould in his efforts to corner the gold market. However, he came out of the venture considerably worse off than his devious partner, who'd surreptitiously offloaded the lion's share of his gold before the price came crashing down as a result of the Black Friday financial panic.

Despite Gould's shady techniques, Fisk continued to work with the scheming robber baron. He used much of the money he made from the alliance to bankroll Broadway shows and support his mistress, Josie Mansfield.

However, Mansfield had another lover, Edward Stokes, who incidentally had dodgy business dealings with Fisk. Following arguments over Mansfield and various questionable business affairs, the complicated love triangle came to a head on January 6, 1872, when a furious Stokes shot Fisk twice at New York City's Grand Central Hotel. Fisk died the following day, aged just 36.

Like the previous robber barons in our list, Daniel Drew also came from a humble background. Born in New York in 1797, he started working on his father's cattle farm from an early age and was poorly educated. In fact, he was more or less illiterate his entire life.

Following his father's death in 1812, the plucky Drew got into cattle trading, which he excelled at. In 1834 he entered the steamship industry, then in its infancy, and became one of the few operators to successfully challenge Cornelius Vanderbilt's near-monopoly.

In 1844, the go-getting entrepreneur opened the Wall Street brokerage Drew, Robinson and Company, which quickly became one of America's leading traders of railroad stocks.

Drew, who engaged in all sorts of unethical business practices despite being a devout Methodist, became involved in the Erie Railroad in 1853. He was initially outsmarted by his arch-rival Vanderbilt, who managed to silently buy up much of the company's stock. Out for revenge, Drew teamed up with Jay Gould and his protégé James Fisk to regain control of the firm.

As we've already mentioned, the trio pulled out all the stops to get the better of Vanderbilt. But the so-called "Erie War" would prove to be Drew's downfall. The treacherous Gould and Fisk betrayed him by driving the Erie stock up, ruining Drew, who had shorted it.

Massively in debt and with no assets left, Drew ended up filing for bankruptcy and died in 1879, dependent on his son William for financial support in his final years.

Born into fabulous wealth in 1837, John Pierpoint Morgan had a tremendous head start in life compared to other names on this list and began his career in his father's banking business.

Morgan would go on to found J.P. Morgan & Co. in 1871, which would become a key funder of the US government as well as a predecessor of three of the biggest banking institutions in the world: JPMorgan Chase, Morgan Stanley, and Deutsche Bank.

In 1885, Morgan reorganized America's chaotic railroad system and was widely credited with improving services, shortening journey times, and bringing down ticket prices.

The banker also helped save the US economy from collapse during the financial panics of 1893 and 1907. Furthermore, Morgan financed the creation of several enormously successful corporations, including US Steel and General Electric.

Yet the business titan attracted a steady stream of criticism throughout his life. During the Civil War, he dodged conscription and instead profited from selling faulty rifles that reportedly "blew off" the thumbs of the soldiers using them. Morgan claimed he was unaware that the weapons were faulty.

His tendency to slash wages while simultaneously cutting workforce numbers was also detested and led to much hardship and numerous workplace accidents.

Morgan was investigated by the US government for antitrust practices and his stranglehold on the country's financial markets. Fed up with the condemnation at home, the all-powerful banker spent his final years in Europe, where he died in 1913.

Born in 1816, Russell Sage (nicknamed "the Sage of Troy" after his hometown), worked as an errand boy in his brother's grocery store in Troy, New York. The hard-working Sage later went into retail on his own and eventually bought out the store of his other brother at the age of 21.

By virtue of his innate business acumen and knack for penny-pinching, Sage founded a lucrative trading company. He then moved into politics and joined the Whig Party. He was elected to the US House of Representatives in 1853, serving two back-to-back terms.

In 1857, Sage lent money to the La Crosse Railroad in Wisconsin and went on to gain a substantial interest in the enterprise, eventually becoming vice president of the business.

Following a move to New York City in 1863, he buddied up with the infamous Jay Gould and engaged in a number of unsavory business practices, and at one point was convicted for charging excessively high interest (up to 80%, according to reports) on money he'd loaned out.

The alliance between Gould and Sage proved fruitful, however, and Sage made a fortune from railroads, telegraph companies, and more, on top of the moneylending.

A legendary skinflint, Sage's miserliness knew no bounds. After surviving a shocking dynamite-based assassination attempt in 1891, he refused to pay any kind of compensation to the clerk who had shielded him from the explosion, who had been left with a lifelong disability as a result.

According to legend, Sage, who passed away in 1906, is said to have wept on his deathbed – not at the prospect of dying, but at the thought of how much his gravestone would cost.

Thankfully, he left his vast fortune to his significantly more generous wife Olivia, who gave away the equivalent of $894 million in today's money to a range of good causes.

Regarded as the original "disruptor," Leland Stanford, who was born in 1824 near Albany, New York, originally trained as a lawyer in Wisconsin.

However, when his legal career was brought to an abrupt halt by a devastating fire, he moved to California in a bid to make his fortune. He quickly found his feet and launched a thriving retail and wholesale business, supplying goods to miners who were participating in the state's Gold Rush.

Stanford quickly moved into politics, helping to form California's Republican party. He was elected governor in 1861 and began investing heavily in the Central Pacific Railroad, which was authorized by Congress in 1862 to build America's first transcontinental railroad.

As president of the railroad company, Stanford exploited his political position to plow state money into the project and enrich himself, partaking in bribery, collusion, and stock watering. 

Tragedy struck in 1884 when Stanford and his wife Jane lost their only child, Leland Jr, to typhoid. He was 15 years old.

Following their son's untimely death, the couple declared that "the children of California shall be our children" and set about creating a university in Palo Alto, spending millions on the institution.

By the time of Stanford Sr's death in 1893, the prestigious Leland Stanford Junior University – better known today by the mononym Stanford – was up and running. It's now one of the finest education establishments in the world and is renowned as a hub of innovation.

Born in 1849 into a Pennsylvania-based farming family, Henry Clay Frick began his career as a bookkeeper.

In the early 1870s, anticipating the burgeoning demand for iron and steel, Frick began building and operating ovens that could produce coke from coal, vital for the process of smelting the two essential metals. The Frick Coke Company was born.

Frick took full advantage of the Panic of 1873 and, with backing from banker Andrew Mellon, bought up extensive coal deposits, creating a formidable coke empire. He eventually bought out the co-founders of the Frick Coke Company. 

Frick teamed up with industrialist Andrew Carnegie in 1889 and was instrumental in developing the Scottish-born tycoon's near-monopoly of the US steel industry.

Humorless and mean, with scant regard for the "little people," Frick was widely reviled. For starters, the heinous robber baron was among those partly accountable for the 1889 Johnstown Flood (aftermath pictured), which killed 2,209 people. Frick and several other individuals had been members of the highly exclusive South Fork Fishing & Hunting Club, which had overseen the modification of a dam in Johnstown, Pennsylvania, with the end goal of creating a fishing lake for the organization's wealthy members.

However, the work caused a devastating flood, with an estimated 20 million tons of water released into the local area.

The fiercely anti-union magnate's refusal to pay decent wages led to the infamous Homestead Strike of 1892, which took place at Andrew Carnegie's steelworks of the same name. Frick sent in men to crush the uprising. A riot ensued and 12 people were killed.

Frick, who died in 1919, wasn't all bad though. On his death, he bequeathed much of his vast estate to charitable causes, giving the equivalent of around $1.9 billion in today's money. He also donated 150 acres of land to the City of Pittsburgh, which later became Frick Park, and his impressive art collection formed the foundations of the Frick Collection, an art museum in NYC.

Often characterized as a robber baron, John D. Rockefeller was actually relatively benevolent. Born in 1839 to a snake oil salesman and his long-suffering wife, Rockefeller, like Frick, began his career as a bookkeeper. He established his first business in the 1850s, trading meat, grain, hay, and other goods.

After identifying the potential of the oil industry, which was in its infancy at the time, the shrewd businessman built his first oil refinery near Cleveland in 1863.

Incorporated in 1870 as Standard Oil, the business went from strength to strength. By 1882, Rockefeller had secured a near-monopoly on the US oil industry.

While his aggressively competitive business practices were disliked by many – the company was deemed an illegal monopoly and was ultimately broken up in 1911 – Rockefeller wasn't necessarily a bad boss. Famously anti-union, he still paid his workers higher than average wages and was also generous with bonuses.

Ultimately, the oil tycoon went on to become one of the world's most celebrated philanthropists. Rockefeller, who was the richest person in modern history, had an inflation-adjusted net worth of more than $400 billion at his peak.

He gave away much of his wealth during his lifetime and, since his death in 1937, his charitable Rockfeller Foundation has provided funding for scientific research and educational institutions. 

Another Gilded Age industrialist who was perhaps more Robin Hood than robber baron, Andrew Carnegie was born in 1835 and survived an impoverished childhood in his native Scotland to become one of the richest tycoons of the era.

His family moved to America when he was a child, and he started working as a so-called bobbin boy in a Pittsburgh cotton factory at the age of 13. By the time he was in his early 20s, the canny entrepreneur-to-be had become the superintendent of the Pennsylvania Railroad.

While working for the railroad, Carnegie invested in the fast-growing oil and iron sectors. By the age of 30, he'd made enough money to leave his job and concentrate on his investing career.

The mogul's most shrewd career move came in the 1870s when he branched out into steel, rapidly gaining a near-monopoly on the industry. Carnegie has been criticized for his harshly competitive approach as well as for events such as the 1892 Homestead Strike, for which many held him ultimately responsible.

That said, the rags-to-riches magnate was seemingly sympathetic to workers' rights, and later admitted to regretting his implicit support of Frick's suppression of the industrial action.

Carnegie sold his steel business to J. P. Morgan in 1901 and then devoted himself entirely to philanthropy. By the time he died in 1919, the deep-pocketed tycoon had given away most of his fortune, which was worth around $375 billion in today's money. His generous donations founded and funded libraries, museums, universities, and peace organizations.

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