When you think of 10 weird siege tactics, the image that springs to mind is the massive gap between sturdy defensive walls and the outlandish methods attackers devised to breach them. For most of warfare’s long story, fortifications out‑paced offensive tech, meaning a solid stone wall often kept armies at bay. This mismatch birthed a cavalcade of creative, sometimes downright bizarre, siege tricks that changed the course of countless battles.
10 Weird Siege Innovations
10 Pigs
King John, often remembered as England’s most troublesome monarch, repeatedly clashed with his barons, leading to the famous Magna Carta charter. After the charter was granted, John promptly tried to invalidate it, sparking another round of rebellion. One of the strongholds that resisted him was a castle in Rochester, where his attempts at diplomacy, bombardment, and bribery all fell short.
John’s engineers finally resorted to tunneling beneath the keep’s walls. When the tunnel was ready, the king ordered “forty of the fattest pigs, the sort least good for eating” to be set ablaze and thrust into the tunnel to scorch the support beams. The resulting inferno was so fierce that the tunnel collapsed, taking a portion of the tower above it down with it.
The rebels managed to hold out a little longer, but the destruction of their defenses and the ensuing starvation forced them to surrender, proving that even swine could be turned into a weapon of war.
9 Dead Bodies
Imagine being stuck outside a fortified city with catapults that can’t breach the walls – morale would be at an all‑time low. In 1346, the Mongol‑led siege of Caffa (now Feodosia in Crimea) faced exactly that dilemma. The attackers, carrying the deadly Black Death, found their own camp teeming with corpses from disease and battle.
Rather than retreat, they loaded those rotting bodies into catapults and hurled them over the walls, hoping the foul stench would incapacitate the defenders. The gruesome projectiles indeed carried the plague, turning the “mountains of dead” into a biological weapon. While Caffa withstood the siege, the diseased corpses likely helped spread the plague to Europe via fleeing ships.
Later, during the protracted 21‑year siege of Candia (modern‑day Heraklion) in the 17th century, the besieged contemplated concocting a poisonous liquid from the spleens and sores of plague victims. Though the plan never materialised, it shows how desperate defenders became when conventional tactics failed.
8 Heat Rays
When the Romans tried to capture the Greek city of Syracuse, they ran into the genius of Archimedes. The famed mathematician allegedly built devices that could lift Roman ships out of the harbor and plunge them to a watery doom. But perhaps his most legendary invention was a “heat ray” that set enemy vessels ablaze.
According to some ancient accounts, Archimedes arranged mirrors—or polished shields—in a tight formation, focusing the sun’s glare onto the Roman fleet. The concentrated sunlight supposedly ignited the tarred hulls, turning the invading ships into bonfires. Modern experiments have demonstrated that, under the right conditions, such a mirror array can indeed start fires on wooden targets, lending credence to the ancient story.
7 Rocket Cats
Franz Helm, a 17th‑century German artillery master, penned a bizarre treatise describing how a cat could be weaponised. He suggested capturing a cat from the enemy’s own town, fastening a small sack—similar to a fire‑arrow—to its back, igniting the sack, and then letting the terrified animal dash toward the nearest fortress.
The text reads: “Create a small sack like a fire‑arrow… bind the sack to the back of the cat, ignite it, let it glow well and thereafter let the cat go, so it runs to the nearest castle or town, and out of fear it thinks to hide itself where it ends up in barn hay or straw it will be ignited.” The illustration makes it appear as though the cat would be propelled like a rocket over the walls.
While there is no solid evidence that such fiery felines ever saw combat, records do describe “fire pigs” being used. For instance, during the siege of Megara, defenders smeared pigs in oil, set them ablaze, and released them to frighten and drive off attacking elephants.
6 Sand
Hollywood often shows defenders dousing attackers with boiling oil or water, but when resources ran low, innovators turned to other scorching substances. During the 1346 siege of Caen, Sir Edward Springhouse was knocked off a ladder, prompting the defenders to hurl burning hay onto him, roasting him in his armor.
Alexander the Great’s assault on the island city of Tyre demanded an even more inventive approach. The city’s defenders heated fine sand until it glowed like embers and then poured it onto the scaling troops. The scorching grains seeped into armor joints, causing excruciating pain that forced many to strip off their protection, leaving them vulnerable to archers. The hot sand also caught the wind, igniting enemy ship sails as it drifted across the water.
5 Greek Fire
Greek fire was the medieval equivalent of a liquid flamethrower, a terrifying concoction that burst into flame on contact with water and clung to anything it touched. Launched from catapults or specialized siege engines, it could scorch enemy ships and breach fortifications. Its exact formula remains a mystery, though scholars suspect a mix of caustic chemicals, pitch, and resin. Only sand, salt, or even urine could extinguish its voracious blaze.
Beyond ship‑to‑ship combat, the Byzantines fielded a hand‑held weapon called the cheirosiphon. Mounted on a siege tower, this device sprayed a stream of Greek fire onto defenders and structures within a besieged city, turning the walls themselves into a fiery deathtrap.
4 Toilets
Modern plumbing is a luxury, but medieval castles often featured a simple board with a hole—known as a garderobe—projecting over the walls to let waste fall away. While one might assume such a setup was only for sanitation, it could also serve as an unexpected point of infiltration.
Château Gaillard, built by Richard the Lionheart and touted as impregnable, fell less than a decade after its construction. King Philip II of France captured the outer bailey but could not breach the inner keep. One observant soldier noticed the castle’s toilet shaft and realized it could provide a narrow, waste‑splattered passage into the keep. He squeezed through, opened a window into the chapel, and allowed French troops to pour into the supposedly unassailable fortress.
3 Exploding Mill Wheel
In 1552, the Ottoman army laid siege to the Castle of Eger in Hungary, hammering its walls with relentless artillery. The defenders, perched atop a hill, faced overwhelming numbers and constant bombardment that began to crumble the outer defenses.
Enter Gergely Bornemissza, a resourceful defender who repurposed heavy millstones—used for grinding grain—by stuffing them with gunpowder. Rolled down the steep hill, these explosive mill wheels amassed significant velocity before detonating amidst the Ottoman ranks, showering the attackers with flaming wood and jagged stone fragments.
2 Piggybacks
In 12th‑century Germany, a patchwork of principalities frequently clashed. In 1140, Conrad III besieged the city of Weinsberg, demanding surrender or facing total destruction. The townsfolk held out, forcing Conrad to threaten a fiery massacre if they refused.
Starvation finally broke the defenders’ resolve, and they agreed to surrender. However, they begged a single concession: that the women be allowed to leave with whatever they could carry. Conrad, displaying a chivalrous streak, granted the request.
When the women exited, the besieging army was stunned to see them bent over, each carrying a male townsfolk on her back. Some contemporaries deemed the scene a humiliating trick, but Conrad reportedly laughed and permitted both the women and the men to depart unharmed.
1 Bees
Walls give defenders the high ground, allowing them to hurl projectiles onto attackers below. Yet besiegers are clever, often digging tunnels or using protective shields to avoid being pelted. When Vikings assaulted Chester in the 10th century, they employed wooden hurdles to deflect thrown weapons.
In response, the city’s defenders first boiled all the beer in massive cauldrons and poured the scalding liquid onto the Vikings, burning their skin. The invaders countered by covering their hurdles with animal hides, forcing the boiling brew to run off. Undeterred, the defenders then seized their beehives and hurled them over the walls.
The angry swarms descended upon the Vikings, stinging them relentlessly. Overwhelmed by the buzzing assault, the Viking forces abandoned the siege, retreating in defeat.