The church of the Blessed Virgin Mary was probably built in the first half of the 13th century, at the earliest in the second quarter of that century and at the latest around its middle. It was mentioned in written sources for the first time in 1335 as ecclesia lapidea – a stone church. It was rebuilt in 1454 and in the mid-18th century, when the window openings were enlarged and the organ choir was inserted. In the 1620s, the church got into the hands of Protestants and in 1654 it returned to Catholicism. It functioned as a parish church, but then it was turned into a branch of the parish in Uniegoszcz, and in 1861 it was subordinated to the parish in Leśna. In the nineteenth century, a sacristy and porch were added to it. Damaged in 1945 and unused it fell into ruin. Protective works were carried out only in 2001.
The church was built in the center of the village Kościelniki Średnie (Mittel Steinkirche) in the vicinity of the former court complex, at the intersection of two routes once running through the settlement: a road from Lubań to Leśna and a road leading to Grodnica. The temple was located on an oval plot surrounded by a wall.
The church was built as an orientated structure, built of unworked stones and rough ashlar sandstone (used in window frames), consisting of a rectangular nave measuring 12.2 x 10.5 meters, a four-sided, almost square chancel measuring 5.2×5 meters and a semicircular apse adjacent to it from the east. From the west, probably in the fifteenth century, a four-sided tower was added.
Originally, both the nave and the chancel were covered with a wooden ceiling. Around 1454, the presbytery was crowned with a stellar vault. The apse window frames indicate that the church originally had careful decorative stonework.
The church is considered one of the region’s most valuable monuments, but is still in a state of uncovered ruin. The original, intact spatial layout has been preserved, with the northern annexes and the tower being later additions. All window and door openings have been transformed, except for one apse window. Of the original architectural details, cornices at the base of the chancel arch between the nave and the presbytery have been preserved.
Krawiec I., Rustecka M., Włochyński L., Romański kościół pw. NMP w Kościelnikach Średnich. Badania i rozważania na temat kierunków ewentualnych ingerencji konserwatorskich [w:] Dziedzictwo architektoniczne Badania oraz adaptacje budowli sakralnych i obronnych, red. E.Łużyniecka, Wrocław 2019.
Świechowski Z., Architektura na Śląsku do połowy XIII wieku, Warszawa 1955.