Sieges have always been the grim theater where armies and civilians clash, and the deadliest sieges in history reveal just how devastating a prolonged blockade can be.
Why the Deadliest Sieges Matter
When a city is surrounded, the battle isn’t just about swords and cannons; it’s a race against starvation, disease, and morale. The ten sieges below show how the stakes rose from regional conflicts to world-shaping catastrophes.
10 Siege Of Szigetvár (1566) 33,000 Killed
Szigetvár sat on the eastern fringe of the Holy Roman Empire, and in 1566 it became the stage for Suleiman the Magnificent’s final campaign. The Croatian governor, Nikola Zrinski, held a garrison of just under 3,000 men against an Ottoman army that outnumbered his by roughly fifty to one.
The siege kicked off on August 6. Despite the overwhelming numbers, Zrinski’s defenses repelled the first Ottoman assaults. After a month of brutal fighting, only 300 Croatian soldiers and their families remained. Suleiman offered Zrinski a high‑ranking post if he surrendered, but Zrinski refused, famously declaring that no one would point a finger at his children in contempt.
Facing inevitable defeat, Zrinski ordered his troops to kill their own wives and children to spare them from the horrors of captivity. The Croatians fought to the last man, and when the Ottomans finally breached the walls, they mercilessly slaughtered the survivors. Suleiman himself never saw the victory; he succumbed to dysentery four days earlier. The Ottoman loss of nearly 30,000 soldiers forced them to retreat, halting their advance toward Vienna and marking a pivotal moment in European history.
9 50,000 Killed
Nuremberg, a major Protestant stronghold, became a bloodbath during the Thirty Years’ War. Swedish King Gustavus Adolf retreated into the city after being chased by the Holy Roman forces led by Albrecht von Wallenstein. Although Adolf commanded nearly 150,000 troops—about 30,000 more than Wallenstein—he failed to bring sufficient provisions.
The Holy Roman army quickly blockaded the city, but Wallenstein’s own supply lines were thin, leading to starvation and a typhus outbreak on both sides. After an 80‑day stalemate, Adolf attempted a breakout at the Battle of the Alte Veste, only to be repelled. With supplies exhausted, he abandoned the city, and the siege ended with roughly 40,000 deaths, most from disease rather than combat.
8 Siege Of Kiev (1240) 48,000 Killed
Kiev, one of Europe’s oldest cities, faced the Mongol onslaught under Batu Khan, grandson of Genghis Khan. After the city executed Mongol envoys, Khan launched a ferocious siege on November 28, beginning with days of catapult bombardment.
On December 5 the walls were breached, and Mongol troops poured into Kiev, slaughtering anyone in their path. Many civilians fled to the Church of the Tithes, which collapsed, crushing countless lives. Of the roughly 50,000 inhabitants, only about 2,000 survived, including the city’s leader Dmytro, who was spared for his bravery. The Mongols departed on December 6, leaving a city reduced to ruins.
7 1604) Over 65,000 Killed
Ostend, now in Belgium, endured one of the longest and bloodiest sieges of the Eighty Years’ War. The newly fortified city attracted a combined Dutch‑English force under General Francis Vere, who hoped to hold it against the Spanish and Archduke Albrecht.
The siege began on July 5, 1601. Defenders eventually mustered nearly 50,000 men, while the Spanish fielded about 80,000 foot soldiers. As the months dragged on, both sides resorted to espionage and betrayal. Albrecht nearly succeeded in turning some Dutch troops against Vere, but the plot was uncovered. After years of attrition, the Dutch and English surrendered on September 20, 1604, and Albrecht entered the ruined city with his wife Isabella, who wept at the devastation.
Negotiations soon followed, leading to a 12‑year truce.
6 Siege Of Baghdad (1258) Over 200,000 Killed
The Mongol horde, led by Hülegü Khan—another grandson of Genghis Khan—targeted Baghdad, the jewel of the Islamic world. After Caliph Al‑Musta’sim refused to surrender, over 100,000 Mongols marched on the city on January 29, 1258.
The siege lasted just twelve days. When the Mongols finally entered, they massacred virtually everyone except the city’s Christians, who were temporarily protected inside a church. Legend says the caliph was trampled to death beneath a carpet. The House of Wisdom, the era’s premier center of learning, was deliberately destroyed, and countless manuscripts were tossed into the Tigris—so many that a horse could reportedly walk across the river of books.
5 1855) Over 200,000 Killed
During the Crimean War, an allied force of British, French, and Turkish troops laid siege to the Russian stronghold of Sevastopol. The conflict introduced early trench warfare and stretched on for eleven months.
When open‑field battles proved futile, the Russians entrenched themselves within the city. Day after day, artillery hammered the fortifications, while the defenders repaired the walls each night. Harsh winter conditions turned the siege into a medical nightmare: cholera and dysentery ravaged the French troops, accounting for most of their casualties.
Eventually the Russians withdrew, allowing the allies to storm the city on September 9, 1855. The siege left a lasting cultural imprint, inspiring works such as Lord Tennyson’s famous poem “The Charge of the Light Brigade.”
4 Siege Of Tenochtitlán (1521) Over 200,000 Killed
The Aztec capital Tenochtitlán fell after a three‑month siege that pitted Hernán Cortés’ Spanish forces against a native population of nearly 300,000. Cortés commanded around 200,000 men, many of whom were indigenous allies disgruntled with Aztec rule.
Initially, the Aztecs held their ground, but a smallpox epidemic devastated their ranks. Recognizing that a door‑to‑door assault was impractical, Cortés bombarded the city with cannons, razing nearly every structure until the Aztecs capitulated.
The siege produced massive civilian casualties—potentially half of the total deaths. A popular myth suggests the Aztecs believed Cortés was the reincarnation of the god Quetzalcoatl, but most scholars agree the Aztec leadership understood he was merely a foreign conqueror.
3 146 BC) Over 460,000 Killed
Carthage, a maritime powerhouse, met its end in the Third Punic War. Roman commander Scipio Aemilianus led over 80,000 troops against a Carthaginian force of 90,000 soldiers and a civilian populace exceeding 400,000.
After a prolonged blockade, Carthage attempted to mount a counter‑offensive but failed. Three years into the siege, Roman forces finally breached the walls, unleashing a ruthless sack. Roughly 50,000 survivors were sold into slavery, and the city was razed. Though later myth claimed the Romans salted the earth, contemporary sources provide no evidence for that practice.
2 Siege Of Jerusalem (70 AD) 1,100,000 Killed
After a Jewish revolt in 66 AD, Roman legate Titus Flavius arrived with 70,000 soldiers to crush the rebellion. Jerusalem’s defenders numbered about 40,000. The Romans surrounded the city with four legions in February, and negotiations faltered when the Jewish historian Josephus was wounded by an arrow.
The siege turned into a nightmare of starvation; residents resorted to eating leather, sewage, and even resorted to cannibalism. In September, Roman forces launched a night assault, breaching the walls and slaughtering the inhabitants. The Second Temple was razed despite Titus’ orders, and the survivors were either enslaved or murdered. By September 7, Jerusalem lay under Roman control.
1 944) 1,000,000–2,500,000 Killed
The Siege of Leningrad, a brutal episode of World War II, pitted Nazi Germany against the Soviet Union for 872 days. The German blockade strangled the city, limiting food supplies to a quarter‑loaf of bread per person per day.
Despite the dire circumstances, the Soviet defenders held the line. In winter, the frozen surface of Lake Ladoga became the “Road of Life,” allowing limited supplies and evacuations of the sick and elderly. When Soviet forces finally pushed the Germans back, the siege was lifted, ending one of the deadliest and longest sieges in recorded history.