[4] It was probably in the late period of Visigoth domination when the city took a new name after the local martyr Santa Irene, whose remains were credited to have been found near the Tagus.

According to period chronicles, the King and a small army managed to take the city after some men climbed the walls during the night and opened the gates.

The story of the conquest of Santarém is told in a heroic tone in the medieval chronicle De expugnatione Scalabis, which celebrates and justifies the power of the first Portuguese King.

The most notable Almohad ruler, Abu Yaqub Yusuf (patron of Averroes and Ibn Tufail), died in Santarém while trying to recapture it during the siege of 1184.

King Fernando I, in particular, was very fond of the city and chose to be buried in the Convent of Saint Francis (Convento de São Francisco).

The city was one of the most important in medieval Portugal, as attested by its large number of monasteries and its royal palace (no longer in existence but was located where the cathedral currently stands).

Pedro de Meneses, first governor of Ceuta (1415–1437) after the Portuguese conquest, is buried in a magnificent Gothic tomb in the Church of the Grace (Igreja da Graça).

In the second half of the 19th century many improvements reached Santarém, like running water, gas light, the building of a bridge over the Tagus and the railway in 1861.

The city of Santarém stands is situated on a plateau, located on the right bank of the Tagus River 65 kilometres (40 mi) northeast from Lisbon.

[12] From 1999 to 2001 the main arena (39°13′05″N 8°41′52″W / 39.21806°N 8.69778°W / 39.21806; -8.69778) was converted into a motorcycle speedway track and held a round of the 1999 European Club Champions' Cup[13] and the 2000 Under-21 World Championship.