Ildephonsus of Toledo was the Bishop of Toledo, Spain from 657 until his death in 667. A cleric and a scholar he is known for his devotion to the Virgin Mary and reportedly experienced a vision of her on the 18th December 665. This church, located on Batalha Square, is dedicated to him with this present construction being completed 1739.
The earliest known reference to a church on this spot dates from 1296 when it is mentioned in a document by Vincente Mendes, the Bishop of Porto, although it is believed that a chapel known as Santo Alifon stood on this site previously. The church was in danger of collapsing so in 1709 it was demolished and the present one begun the following year in 1710. The construction took 29 years to complete and although the architect remains unknown, the names of carpenters, stone masons and locksmiths who worked on the site are recorded.
The church has been damaged several times, by a storm in 1819, Siege of Porto in 1833 and each time it has been repaired and modified. As late as 1996, nineteen graves were discovered during renovation works in an area that corresponds to the original chapel courtyard.
Constructed of granite the building is known for its azulejo tiles that decorate the façade. Designed by Jorge Colaço and place there in 1932. More than 11,000 azulejo tiles depict the scenes from the life of Saint Ildephonso as well as imagery from the gospels.
Located on the main alter, this retable (framed altar piece) was designed by Nicolau Nasoni and created by Miguel Francisco da Silva was installed in 1945. Nasoni, born in San Giovanni Valdarno in Tuscany, Italy, was one of the most influential figures in Baroque Portuguese architecture of the 18th century by introducing a more theatrical style. He is buried the Clérigos Tower located nearby.
Today standing to the left of the church it was originally located on the steps facing Rua 31 de Janeiro to align the church with the bell tower of Clérigos Church (Igreja de Clérigos). In 1924 due to construction it along Rua de Santa Catarina it had to be moved to its present site.