7 of the Most Unusual Fighting Forces in History

Armies have always sought to bring the biggest and strongest soldiers into their ranks, but King Frederick William I of Prussia turned it into an obsession. In the early 18th century, the military-loving monarch tried to assemble the tallest troops in Europe into an elite regiment nicknamed the “Potsdam Giants.” Though they never saw combat, these enormous grenadiers grew to become the most impressive collection of big men this side of a pro basketball team. Several members were seven-footers, and one Swedish recruit was said to stand eight and a half feet tall.

King Frederick was constantly on the lookout for potential Potsdam Giants, and he was willing to beg, borrow and steal to get them. He spent a fortune hiring outsized mercenaries and buying tall soldiers off other militaries, and instructed his agents to shanghai exceptionally tall civilians and conscript them into the unit. In a bizarre attempt to breed future recruits, he even compelled his largest troops to marry and have children with tall women. King Frederick derived great joy from the giants—he was known to have them march through his bedroom to cheer him up when he was ill—but they were also a significant drain on royal coffers. After he died in 1740, his son disbanded the unit and used the savings to fund four additional regiments of normal-sized soldiers.

According to Norse lore, berserkers were a feared class of Viking warriors known for fighting with a hysterical, wild-eyed fury. Neglecting chain mail or other armor, these imposing shock troops supposedly went into battle wearing bear and wolf pelts or even bare-chested. Once in combat, they killed, raped and pillaged with reckless abandon, to the point that some Norse sagas claimed they could physically transform into ferocious beasts. The berserkers’ skill in battle made them much sought after as soldiers and royal bodyguards, but they were also feared and even hated by their fellow Vikings. They could become so drunk with rage that they would inadvertently turn on their friends, and when not in combat they often raped and murdered their allies to satisfy their bloodlust.

Just how the berserkers tapped into their famous anger is uncertain. They may have been connected to secretive cults devoted to the Norse god Odin, so their rituals were likely mysterious even to their contemporaries. Most scholars believe they simply worked themselves into a hypnotic trance, but others have speculated that they may have gotten blind drunk or consumed a certain species of hallucinogenic mushroom.

One of the most feared and famous armies of antiquity, the Immortals were a 10,000-strong fighting force associated with the Achaemenid Empire of Persia. These spear-toting warriors first appear in the Greek chronicler Herodotus’s account of the Persian invasion of Greece, where they are described as “the best…and most magnificently equipped” soldiers operating under the command of King Xerxes. According to Herodotus, the nickname “Immortals” arose because the unit always had the same number of troops. If even a single Immortal fell sick or died in battle, he was immediately replaced so that the unit’s strength was “never more nor less than 10,000.”

While the Persian army was a multinational force, only those with Persian or Medic ancestry were allowed to serve in the Immortals, and they were adorned with gold jewelry to signify their high status. The 10,000 primarily served as the king’s personal bodyguards, but they also took to the field in times of war. Their most famous action came during the Persian victory at the Battle of Thermopylae in 480 B.C., when they bypassed a blocked path and ambushed the Spartan-led Greeks from the rear.

In the summer of 1944, the U.S. Army gathered a select group of artists, designers and sound effects experts for a particularly unusual task: building a phantom army. Inspired by a trick originally pulled by British forces in North Africa, the 23rd Headquarters Special Troops—better known as the “Ghost Army”—used inflatable rubber tanks and jeeps, sound effects and other subterfuge to deceive the Germans about the actual size and location of Allied forces. The unit took part in more than 20 missions, many of which employed artistry and illusion on a scale that rivaled a Hollywood movie.

Painters and illustrators designed fake uniforms and dummy vehicles; sound engineers broadcasted phony radio traffic and blasted sound effects that mimicked the racket of an army on the move; and actors spread misinformation in the hope it would be picked up by Nazi spies. When the ruse worked, the unit was able to give the impression that U.S. forces were larger and more mobile than was actually the case. During one mission, the Ghost Army even plugged a hole in General George Patton’s lines for several days without being discovered.

The Ghost Army’s actions were kept under wraps for several decades after the end of World War II, and it wasn’t until 1996 that its unusual contribution to the war effort finally became public knowledge. By then, many of its members had gone on to distinguished careers in the art and design industries. Among others, fashion designer Bill Blass and artists Ellsworth Kelly and Arthur Singer were all veterans of the unit.

The history of the Gurkhas stretches back to 1814, when British colonial forces clashed with the city-state of Gorkha during the Anglo-Nepalese War. Though significantly outgunned, the Nepalese “Gurkha” warriors inflicted heavy casualties on the British and eventually forced them into a peace treaty. Impressed by the Gurkhas grit and tenacity, the British included a stipulation in the peace deal allowing the Nepalese fighters to serve as volunteer soldiers in the East India Company’s army.

Gurkhas were later incorporated into the regular British Army, and they went on to serve in nearly every major British military action of the 19th and 20th centuries. Famous for their curved kukri knives and the motto “Better to die than be a coward,” they earned a reputation for their loyalty and extreme bravery under fire. Gurkhas won nearly 2,000 citations for valor during World War I alone, and 13 have been awarded the Victoria Cross—Britain’s highest military honor. To this day, the British Army handpicks around 200 new Gurkhas each year from a pool of nearly 30,000 Nepalese youths. Recruits go through a grueling screening process that includes a long-distance run through the Himalayas while wearing a wicker basket filled with 70 pounds of rocks.

The Mormon Battalion has the unusual honor of being the only unit in U.S. Army history comprised entirely of Latter Day Saints. The faith-based fighting force originally came about in July 1846 after negotiations between Brigham Young’s church leaders and the U.S. military. While the Mormons hoped the battalion would pave the way for their exodus to the American West by providing equipment and soldiers’ pay, President James K. Polk saw it as a means to help make the Latter Day Saints friendly allies of the U.S government.

Although it never saw combat, the 500-man Mormon Battalion became one of the most well traveled units in American history. The men began their service by making a grueling march out of Iowa and through hostile Indian land to Santa Fe. From there, they proceeded through the wilds of Arizona and into southern California, where the performed garrison duty around San Diego and Los Angeles. The short-lived battalion was mustered out of service in July 1847, at which point most of its members headed north to join their fellow Mormon pioneers in the Utah Territory.

The Monuments, Fine Arts and Archives section—better known as the “Monuments Men”—was a special unit tasked with preserving Europe’s cultural heritage during World War II. This small, handpicked collection of art historians, museum curators and scholars originally ventured to the front lines to help prevent historically important buildings and other landmarks from becoming casualties of war. One of their most important tasks was ensuring that culturally significant structures were not unintentionally destroyed during the Allied push into Europe. Members of the unit designed special maps instructing pilots on which areas to avoid on their bombing runs, and took steps to preserve and restore landmarks that had already been damaged.

Near the end of the war, the unit’s focus changed to tracking down and recovering priceless paintings and sculptures looted by the Nazis. As Hitler’s regime crumbled, the Monuments Men uncovered thousands of artworks secreted away in castles and salt mines and worked to return them to their rightful owners. Among others, the unit rescued masterpieces by luminaries such as Rembrandt, Da Vinci, Michelangelo, Vermeer and Botticelli.