St. Thomas Church is associated with a number of well-known composers such as Richard Wagner and Felix Mendelssohn Bartholdy, but mostly with Johann Sebastian Bach who worked here as a Kapellmeister (music director) from 1723 until his death in 1750. Today, the church also holds his remains. Martin Luther preached here in 1539.
There has been a church at the current site of the Thomaskirche at least since the 12th century. Foundations of a Romanesque building have been discovered in the choir and crossing of the current church. Between 1212 and 1222 the earlier structure became the church of the new St. Thomas Monastery (Stift) of the Augustinian order.
The current building was consecrated by Thilo of Trotha, the Bishop of Merseburg, on 10 April 1496. The reformer Martin Luther preached here on Pentecost Sunday in 1539. The monastic buildings were demolished in 1541 following the monastery's dissolution. The current church tower was first built in 1537 and rebuilt in 1702. Chapels added in the 17th century and an ante-building along the northern front of the nave with two stairways were removed at the end of the 19th century.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.