When armies encircle a city, they hope to crush resistance quickly, but history shows some sieges stretched into decades, turning fortresses into marathon battles. Below we tally the ten longest sieges ever recorded, each a testament to endurance, ingenuity, and the high price of war.
Why the Longest Sieges Matter
Extended blockades tested supply lines, forced innovations like trebuchets and naval resupply, and often reshaped regional politics. Understanding these protracted conflicts helps us appreciate the human cost behind the headlines of battle.
10 Siege Of Candia21 Years
The Siege of Candia, now Heraklion on Crete, holds the record for the longest siege in history, dragging on for an astonishing 21 years. Babies born at the start of the conflict were old enough to wield swords by the time the walls finally fell.
In 1644 the Knights Hospitaller raided an Ottoman convoy, prompting the Turks to dispatch a massive force of 60,000 men against Candia, which was defended by Venetian allies. The siege officially began in 1648. Attempts to break it in 1666 and 1669 failed, and Ottoman assaults could not breach the formidable walls. By the end, Captain General Morosini was left with just 3,600 fit soldiers. In 1668 he negotiated honorable surrender terms that allowed the remaining Christians to leave the city safely.
9 Fall Of Philadelphia12 Years
The city we’re talking about isn’t the American one, but the medieval Turkish town now called Alasehir. From 1378 to 1390 it withstood a vastly superior Ottoman army, lasting twelve hard‑fought years.
A disastrous Byzantine civil war forced Emperor Manuel II to solicit Ottoman help, with the price being the neutral city of Philadelphia under the Knights Hospitaller. The residents weren’t keen on Ottoman rule and held out stubbornly. By 1390 every other Asian Minor city had capitulated, yet Philadelphia still resisted. The Ottomans finally called in the two Byzantine civil‑war leaders to the blockade, and Sultan Bayezid managed to enter the city after a twelve‑year siege, a humiliation for both the Ottoman and Byzantine sides.
8 Siege Of Ishiyama Honganji10 Years
In Osaka, Japan, the cathedral‑fort of Ishiyama Honganji fell under Oda Nobunaga’s assault in 1570. Thanks to an extensive defensive network, the stronghold endured a ferocious ten‑year siege.
By August 1570 Nobunaga’s 30,000‑man army erected a ring of forts around the temple. A month later, a surprise counter‑attack by the 15,000 defenders destroyed several of those outposts. Starvation attempts failed because the fortress received supplies from the sea via Nobunaga’s enemies. Even a 3,000‑man assault in August 1567 was repelled, thanks to 51 outposts the defenders had built. It wasn’t until 1578 that a fleet finally cut the supply line, and by 1580 the garrison ran out of food and ammunition, forcing surrender.
7 Siege Of Thessalonica8 Years
The Ottoman Sultan set his sights on Thessalonica in central Macedonia in 1422, seeking revenge against the Byzantines for inciting rebellion. The city was handed to Venice for its defense, and the Venetians managed to hold out for eight grueling years.
The siege began with a naval blockade that starved the inhabitants. By 1430 the Venetians, unable to raise more than a few thousand troops, faced a massive Ottoman army. The city finally fell, and nearly 10,000 citizens were taken as slaves.
6 Siege Of Drepana8 Years
Drepana, a Carthaginian naval fortress on Sicily, endured a relentless Roman assault beginning in 249 BC. The combined land and sea siege lasted eight years, until 241 BC, and the defenders even managed to sink an entire Roman fleet.
In total, Carthaginian ships sank or captured 93 Roman vessels while losing none of their own, allowing the city to be resupplied by sea despite the land blockade. By 241 BC the Romans rebuilt their fleet, intercepted the main Carthaginian navy, and forced the end of the First Punic War along with the fall of Drepana.
5 Siege Of Solovetsky Monastery8 Years
The Solovetsky Monastery Uprising saw around 800 monks, part of the Old Believers sect, defy Russian tsarist forces from 1668 to 1676. Their fortified monastery became a surprisingly stronghold against the empire.
Local peasants and even Russian soldiers smuggled food past the blockade, bolstering the monks’ resistance. By 1674, over a thousand Russian soldiers and heavy artillery joined the siege, while the monks erected new fortifications. In 1676 a monk betrayed a hidden window, allowing Russian troops to storm the monastery, massacre the defenders, and leave only sixty survivors. Ironically, the kitchen still held enough provisions to have prolonged the siege for many more years.
4 Siege Of Tripoli7 Years
The Crusader siege of Tripoli began in 1102 and lasted seven years, ending in 1109. Count Raymond IV of Toulouse led the effort to secure the Holy Land during the First Crusade.
Knowing his 300 men were insufficient, Raymond built the Citadel of Raymond de Saint‑Gilles to block land access. In September 1104 the city’s ruler, Fakhr al‑Mulk, attacked the citadel, burning a wing and injuring Raymond, who died five months later. On his deathbed, Raymond negotiated a deal that halted attacks on the fortress in exchange for trade routes. By 1108 food remained scarce, and some Tripolitan nobles sold secrets to the Crusaders, only to be executed. In 1109 the Crusader King of Jerusalem arrived with reinforcements, finally capturing the city.
3 Siege Of Harlech Castle7 Years
After the crushing Yorkist defeat at Towton in 1461, the Lancastrian queen Margaret of Anjou fled to Harlech Castle, drawn by its natural defenses. The castle became the last Lancastrian stronghold.
Following Edward IV’s coronation, attempts to starve Harlech failed due to its proximity to the sea. By 1464 the rest of the Lancastrian holdings had fallen, but Harlech held out for another four years, even receiving French reinforcements and launching raids. Finally, in 1468 Edward IV mustered a 10,000‑man army to confront a garrison of roughly 50 defenders. The castle surrendered after negotiations, ending the Lancastrian resistance.
2 Battle Of Xiangyang6 Years
In 1267 Kublai Khan ordered his commander Aju to lay siege to Xiangyang. The city’s 8,000 defenders faced a Mongol force of 100,000 troops and 5,000 ships—because, well, they were Mongols.
The besiegers built a chain of forts to blockade the city and brought 100 trebuchets. The defenders reinforced the walls and added netting to absorb rock impacts. From 1267 to 1271, attempts to relieve the city of 200,000 troops were repelled. In 1272 a 3,000‑man force broke through and supplied the city, but could not return. The siege finally broke when a test shot from a counter‑weight trebuchet hit a stone bridge, causing panic. Aju then massacred a neighboring city’s population to terrorize Xiangyang, forcing its surrender.
1 Great Siege Of Gibraltar3 Years, 7 Months
The Great Siege of Gibraltar (1779‑1783) was an unsuccessful attempt by Spanish and French forces to capture the British fortress during the American War of Independence. It remains the longest siege in which the British Armed Forces have taken part.
By winter 1779 the garrison was low on supplies. Admiral George Rodney broke the Spanish blockade with 129 ships, resupplying the fort and evacuating civilians. On 13 September 1782, ten French and Spanish floating batteries, armed with 138 heavy guns, launched a massive assault. The 7,500 British defenders answered with hot shots, igniting three floating batteries in spectacular mushroom clouds and forcing the attackers to retreat. A further 65 ships slipped past the blockade the following month. By February 1783 the Spanish and French withdrew, leaving Gibraltar firmly in British hands.