During the Albigensian Crusade the town sided with the Count of Toulouse, Raymond VII but in 1226, after a three-month siege by Louis VIII of France, Avignon capitulated and was forced to dismantle the early walls and fill in the moats.

There were originally twelve gates controlling access to the city but this number was reduced to seven when the fortifications were modified between 1481 and 1487 during the French Wars of Religion.

[3][4] This wall is mentioned by the Gallo-Roman historian Gregory of Tours when describing the siege of the town by the Frankish king, Clovis I, in around 500 AD.

The double walls extended around a perimeter of approximately 3 km (1.9 mi) and enclosed an area of around 45 ha (110 acres).

In 1226 the French king, Louis VIII, descended the Rhône valley with a papal legate and a large army en route to a new campaign against the Albigensians.

Avignon refused to open its gates but after a siege lasting three months (10 June until 12 September) the city was forced by famine to capitulate.

[10] The path of early walls in northwest corner of the town near the Pont Saint-Bénézet is obscure due to the subsequent changes to the fortifications in this important area.

[15] The pairs of arched gateways were retained long after the double set of walls had been demolished and are depicted on 16th and 17th century maps of the town.

In the covered section of the moat, which now serves as a main sewer, the external surfaces of the 13th century walls are clearly visible as are the lower portions the semi-circular towers.

[24] Prompted by the threat from the bands of marauding mercenaries (free companies) that were roaming elsewhere in France, sometime between 1355 and 1357 Pope Innocent VI decided to protect the expanded town with a new set of walls.

[28] The pope may have initially provided small sums for the project but from January 1358 the construction costs were paid for by a tax (gabelle) on wine brought into the town.

[30] While work on the wall was progressing the town came under attack from unemployed mercenaries whose numbers increased when a truce in the Hundred Years' War was agreed in Bordeaux between the English and French forces in March 1357.

In 1358 Pope Innocent VI bought off a group of mercenaries led by Arnaud de Cervole (known as the Archpriest) with a ransom of 1,000 gold florins.

[37] No wall was required for a stretch of 270 metres (300 yd) at the north of the town which was protected by the steep sides of the Rocher des Doms.

[38] Except for a section near the Rhône between the Porte Saint-Jacques and the Rocher des Doms the walls were surrounded by a moat which was supplied with water from the Sorgue and the Durance.

[40] During the western schism (1378 to 1417) that followed the Avignon papacy, Aragonese troops paid by the antipope Benedict XIII defended the papal palace complex against attacks by people from the town.

The work was initiated by the papal legate Archbishop Giuliano della Rovere who subsequently became Pope Julius II.

[20] In 1561 Pope Pius IV sent his cousin, Fabrizio Serbelloni, to organise the defence of the town against the Huguenots during the French Wars of Religion (1562–1598).

In 1679 some of the exterior fortifications protecting the Porte Saint Michel were transformed into a triumphal arch dedicated to Pope Innocent XI (in post 1676–1689).

In 1755–1757 a new gatehouse designed by the architect Jean-Pierre Franque was built 50 metres west of the old gate at the end of Rue Palapharnerie.

The walls surrounding Avignon were spared a similar fate although they were threatened with partial demolition on several occasions.

[53][54][55] For the city of Avignon, an advantage of keeping the walls intact was that with only seven entrances it made collecting the octroi easier.

[62][63] Each of the city gates was modified to facilitate the construction of a temporary cofferdam to prevent the river water entering the town.

A sluice gate on a small sewer failed at the end of Rue Conduit Perrot near Porte Saint-Lazare at the northeast corner of the town.

Within the walls, some areas to the east of the centre were flooded to a depth of a few tens of centimeters due to the high level of the water table.