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The longest sieges in medieval history 

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Sieges were a frequent occurrence in the medieval era. Some were mercifully short and lasted only days or weeks. But some dragged on for years, becoming punishing ordeals for soldiers and civilians alike.

Here are some of the longest recorded sieges to have taken place, from a standoff in the heart of the Byzantine Empire to the epic takedown of Philadelphia (no, not that one).

1. The Siege of Constantinople

Length of siege: 4 years (or perhaps longer)

Throughout the early medieval period, Muslim Arab dynasties repeatedly came to blows with the Byzantine Empire. One of these dynasties was the Umayyad Caliphate, whose forces attempted to capture the Byzantine capital of Constantinople around 674 AD.

The Arabs established a base near the city and mounted repeated assaults over four years. Historical details of the siege are hazy, and various dates have been proposed. However, it’s generally thought the siege lasted four years, culminating in the invaders being seen off by a fleet of Byzantine ships equipped with 'Greek fire’ – early flamethrowers whose precise composition is still a mystery to historians today. The end of the siege was a major victory for the Byzantine Empire, consolidating its power in the region.

2. The Siege of Harlech Castle

Length of siege: 7 years

The longest siege in British history unfolded at Harlech Castle in Wales, between 1461 and 1468. It took place during the Wars of the Roses when the houses of York and Lancaster were grappling for control of the country. By 1461, Harlech Castle was one of the few Lancastrian strongholds left and commanded by a veteran Welsh soldier named Dafydd ap Ifan ap Einion.

Even while it was besieged, the castle was a hive of Lancastrian operations and a thorn in the side of Edward IV’s Yorkist regime. The garrison inside the castle also stubbornly refused the king’s offers of a pardon if they would surrender peacefully.

Eventually, in 1468, the Yorkists unleashed a full attack on the castle, bombarding it into submission. Though some of the Lancastrians were executed, Dafydd was pardoned. The famous Welsh patriotic song Men of Harlech featured in the films Zulu and How Green Was My Valley, is said to commemorate the events of the siege.

3. The Siege of Tripoli

Length of siege: 7 years

The siege of Tripoli (located in present-day Lebanon, not to be confused with the capital of Libya) began in 1102 and dragged on for seven long years. It was led by Raymond IV, Count of Toulouse, who had, until recently, been embroiled in the First Crusade. He and his Crusader army were set on conquering the wealthy Muslim city, but local leader Fakhr al-Mulk wasn’t about to give in without a fight.

A few years into the siege, al-Mulk’s forces attacked the Crusader base. Many would-be invaders were killed, and Raymond himself died shortly afterwards. However, the people of Tripoli struggled in the face of food shortages and had to submit. It was duly turned into a Crusader state, known as the County of Tripoli.

4. The Siege of Thessalonica

Length of siege: 8 years

In 1422, the sultan of the Ottoman Empire decided to punish the Byzantine Empire when the latter supported a rebellion against him. The sultan’s target was Thessalonica (modern-day Thessaloniki in Greece), and what ensued was a particularly arduous eight-year standoff.

Lacking the resources and manpower, the Byzantine governor of Thessalonica passed control of the city to the Republic of Venice. The Ottomans were unimpressed by the Venetians’ new claim over the city and formed a naval blockade which caused near-starvation for the inhabitants. Many citizens also resented their new Venetian overlords because of their profiteering and authoritarian rule. Eventually, the Ottomans stormed the city using siege engines and archers, sacking Thessalonica in 1430.

5. The Fall of Philadelphia

Length of siege: 12 years

One of the longest sieges of all time commenced in 1378 in Philadelphia, a Christian Greek city in what is now Turkey. A thriving trading centre known for its leather and silk goods, Philadelphia was technically part of the Byzantine Empire. However, it was effectively an independent community located amid hostile Ottoman territory.

The Byzantine rulers agreed to hand control of the city over to the Ottomans in return for military aid. But the citizens of Philadelphia resisted the transition and were therefore besieged by Ottoman forces year after year. The humiliating denouement finally came in 1390, when the two co-emperors of the Byzantine Empire were forced by the Ottoman sultan to accompany the besieging troops and order the people of Philadelphia to stop resisting. And so the 12-year siege came to an end.