The church was built by Spycimir Leliwita after the town’s location in 1330. As a parish church, it was listed for the first time in the Peter’s Pence in 1346. It was built in the northwestern part of the town at its highest point. At the end of the 14th century, the first chapel of Holy Cross was added to the south wall of the church, founded by the Cracovian subcamerarius, grandson of Spycimir Leliwita. In 1400 the bishop of Cracow Piotr Wysz, at the request of Jan of Tarnów, raised the Tarnów church to the dignity of the collegiate church and called a collegiate chapter in it. Due to the rising of the church, it was probably expanded to include the presbytery, the canyon sacristy and the tower which was lower masonry and upper wooden. In the 15th century the upper part of the tower was built, and the chapels were added to the church. The next two centuries have added new elements in baroque style. It was a chapter erected after 1617, and a Chapel of Saints Relic, built in 1712. In this form the collegiate survived until the Partitions of Poland.
By the end of the 18th century Tarnów became the capital of a new diocese, and the collegiate church was decided to enlarge. After 1826, both rows of chapels were joined, thus forming two aisles, giving the church the shape of a three-nave basilica. In the years 1889-1900, the temple was given its present appearance. The chancel was extended by adding a three-sided apse, a new musical choir was erected, the tower was raised, and most of the outer walls were faced with a new brick.
In its original, fourteenth-century form, the church was an towerless and aisleless building. During the Middle Ages, it was surrounded by chapels, a rectangular chancel was added on the east side, and a tower on the west side. Its original height is unknown, today it measures 72 meters. The interior of the current main nave is vaulted. The former chapels, and today’s aisles were mostly stellar, and the chapel of St. Cross received a seven-sided vault.
Krasnowolski B., Leksykon zabytków architektury Małopolski, Warszawa 2013.
Website wikipedia.org, Bazylika katedralna Narodzenia Najświętszej Maryi Panny w Tarnowie.