The Basilica of Our Lady (Dutch: Basiliek van Onze-Lieve-Vrouw; Limburgish: Slevrouwe [sləˈvʀɔwə]) is a Romanesque church in the historic center of Maastricht, Netherlands.

[1] It is clear that the chapter of Saint Servatius was the more powerful institution in Maastricht, with strong ties to the emperors of the Holy Roman Empire, but throughout the Middle Ages the two churches remained rivals.

[4] The building is largely Romanesque in style and is considered an important example of the Mosan group of churches that are characterized by massive westworks and pseudo-transepts.

The westwork, built of carbonic sandstone, dates from the early 11th century and is flanked by two narrow towers with marlstone turrets.

During the building campaign the original plan for the eastern part of the church was abandoned and a new scheme, based on the newly finished choir of St. Lambert's Cathedral, Liège, adopted.

[5] The current, heavily restored choir towers are roofed with Rhenish helms of stone rather than shingling.

Cuypers also removed the white plastering of the late Baroque period and had several altars built in a Romanesque or Gothic Revival style.

A precious baptismal font by the Maastricht metalworker Aert van Tricht (c. 1500) survived but was stripped of most of its ornaments.

Among the works of art owned by the church are a wood panel of The dream of Jacob (Flemish, c. 1500–1550), a large canvas with the Holy Family (Southern Netherlands, c. 1600), a large painting of the Crucifixion (Southern Netherlands, 17th century), two paintings attributed to Erasmus Quellinus II, one of Saint Cecilia and one of Saint Agnes (17th century), a 14th-century German Pieta, two 15th-century statues of the Virgin Mary (including the famous one in the Star of the Sea chapel), an Anna selbdritt and a Saint Christopher, both attributed to the Maastricht sculptor Jan van Steffeswert (c. 1500).

A close relationship has been established between the Romanesque sculpture in Our Lady's and that in the Basilica of Saint Servatius in Maastricht, the Church of St Peter in Utrecht and the Schwarzrheindorf double chapel in Bonn.

Pope Pius X crowned the venerated Marian image on 15 August 1912 via the Bishop of Roermond, Joseph Hubert Drehmanns.

The Basilica of our Lady possesses an important historical church treasure consisting of relics, reliquaries, textiles and liturgical objects.

From the 14th century onwards it had a separate treasury room (Dutch: schatkamer), which at one point was located in the Tower of Saint Barbara (also the church's archives).

It is believed that the choir gallery of Our Lady's was specifically built in the 12th century for the public showing of the recently acquired relics from Constantinople.

The relics display, especially at the time of the Septennial Pilgrimage (Dutch: Heiligdomsvaart), drew large numbers of pilgrims from all over Europe, bringing in revenue for the churches.

Many gold and silver objects were melted down in order to pay for war taxes during the tumultuous period after the French conquest of Maastricht in 1794.

[14] The treasure of the basilica of Our Lady as it is today consists of reliquary boxes, cases or busts made of (gilded) silver or copper, silvered lead, brass, ivory, horn, bone and wood; chalices, patens, monstrances and other liturgical implements made of silver, silver-gilt, brass or tin; ecclesiastical vestments and ancient fabrics used for wrapping relics; antique books and manuscripts; paintings, prints and sculptures; and some archeological finds.

The highlights are: Furthermore, the treasury is home to a collection of devotional objects (crucifixes, statuettes, rosaries, scapulars, pilgrim badges, and In memoriam cards) belonging to the foundation "Santjes en Kantjes".