[1] By the main entrance to the fortified complex, the Puerta del León [Lion's Gate], are the remains of the Roman wall dating to before 26-16 BC.

[2] The Court session held there in 1214 is notable for being the occasion on which James I of Aragon, then aged six, was recognised by the Catalans and the Aragonese and crowned King of Aragón.

It shares the hill with the Old Cathedral of Lleida, the foundation stone of which was laid in 1203 following the conquest of the Muslim city of Larida in 1149 by the Catalan counts Ramón Berenguer IV and Ermengol VI.

On capturing Lleida that year, he likely invested Guillem Ramon de Montcada, the father of William I, Viscount of Béarn, as the castà (castellan) of La Suda.

[11] François Collignon's contemporary (after 1647 but before 1687) middle oblique view of the start of the siege shows, among other details, the citadel—containing the castle, the cathedral and the bishop's palace—within the city walls (and Fort Gardeny outside), as well as the lines of circumvallation abandoned just six months before by Harcourt and which the Spanish had failed to destroy.

[13][14] The garrison of 2,500 Grand Alliance (League of Augsburg) troops, under its commander, General Heinrich von Hesse-Darmstadt,[12] younger brother of Prince George of Hesse-Darmstadt,[note 2] who was killed at the Siege of Barcelona (1705), included the British Royal Regiment of Fusiliers, which had left Plymouth in February 1706, then numbering 834 men under Lt. Col. Hunt Withers, now reduced to 500 men.

[16] At the siege of Lérida (29 April to 13 May 1810), an Imperial French army under Louis Gabriel Suchet besieged a Spanish garrison led by Major General García Conde.

There had also been attempts since 1886 to declare the Old Cathedral a national monument but, due to the Carlist Wars, the government was more interested in keeping it as part of the city's defences, and it was not until 1918 that it attained that status, although it was not until several years later that it was demilitarised and restorations works could commence.