Königsberg - Cathedral of the Blessed Virgin Mary and St Adalbert
The construction of the Gothic cathedral began around 1330. However, the date of 13 September 1333 is considered to be the beginning of the construction, when the Bishop of Samibia, John Clare, after temporarily stopping the work, signed an agreement between the Order and the Church to build the cathedral without any defensive elements, as there was already a fortress nearby.

Initially, the cathedral was the seat of the Catholic bishops of Sambury. From 1525 to 1945, it was a Lutheran church. It is one of the few surviving monuments of the city's pre-war architecture. Today, the cathedral functions mainly as a cultural institution. It houses, among other things, concert halls and the Immanuel Kant Museum. Classical and religious music concerts are held in the cathedral, and Catholic, Orthodox and Protestant services are occasionally held .

Epitaph of Boguslaw Radziwill and his wife Anna Maria
Born in 1620 in Gdansk, Duke Boguslaw Radziwill was one of the most prominent representatives of his family in the 17th century, from 1657 until his death he held the office of governor of the Ducal Prussia. In Poland, his character is mainly associated with Henryk Sienkiewicz's "Deluge", in which he is portrayed as a villain, explaining to Andrzej Kmicic that "the Republic is a stance of red cloth, pulled by Swedes, Chmielnicki, Hyperboreans, Tartars, the Elector and whoever lives around. And we, together with the Prince Voivode, have said to ourselves that there must be enough of this cloth left in our hands for a coat; therefore we not only do not bother to pull, but also pull ourselves'.

The negative image of the magnate, the rake, the adventurer and, above all, the cynical traitor, was further strengthened by director Jerzy Hoffman in the much-loved film adaptation of the second part of the Trilogy, with Leszek Teleszyński playing the role of Bogusław Radziwiłł.

This wealthy and influential representative of the Radziwiłł family, protector and defender of Protestantism, died a sudden death from an attack of apoplexy on 31 December 1669, while hunting partridges near Königsberg. He was buried in the Cathedral of the Blessed Virgin Mary and St Adalbert on Königsberg's Knipawa Island.

The cathedral has an epitaph of Prince Boguslaw and his wife Anna Maria. Its creators were probably Dutch sculptors working in the workshops of Gdansk. They made the background from black Belgian marble and the ornaments from light English alabaster. The epitaph was funded by Boguslaw Radziwill himself after the death of his wife. The work was completed after the magnate's untimely death in 1669.

In August 1944, during the air raids and bombardment of the city by Soviet troops, the epitaph was almost completely destroyed. The cathedral itself was severely damaged by bombs and fire. The vaulting and roof ceased to exist, and debris falling on the epitaph caused catastrophic damage.

Since the 1990s, reconstruction of the cathedral has been underway. The interior of the church has been adapted for cultural purposes. During the construction work, a large part of the inscription tablet on the left side of the epitaph was found. This finding contributed significantly to the restoration work carried out in 2007-2008.

At the beginning of 2007, on the basis of the research carried out in Kaliningrad, a conservator's opinion was drawn up and forwarded to the Russian side through the Consulate General of the Republic of Poland in Kaliningrad. The Ministry of Culture of the Government of the Kaliningrad Region agreed to allow Polish specialists to undertake the work.

In 2007, the first stage of the work was carried out, consisting of the installation of the existing slabs, filling in of cavities, removal of weathering and deepening of the inscriptions. In December 2008, the architectural background and busts of the two spouses were reconstructed - thus completing the full reconstruction of the object, carried out by a team of conservators consisting of: Hanna Kazberuk, Andrzej Kazberuk and Dariusz Sroczynski, under the substantive supervision of Dr. Janusz Smaza, fully financed by the Ministry of Culture and National Heritage within the framework of the Programme "Protection of Cultural Heritage Abroad" at the request of the Culture and Art Beyond Borders Foundation.

Epitaph of Celestyn Kowalewski
In 2014, within the framework of the Programme of the Ministry of Culture and National Heritage "Protection of Cultural Heritage Abroad", at the request of the Foundation for the Culture and Heritage of Polish Armenians, the conservation of the epitaph plaque of Celestyn Kowalewski (1700-1771) was financed. Placed on the northern wall of the Königsberg Cathedral, the plaque was funded by Celestin Kowalewski's daughter, Katarzyna.

Celestyn Kowalewski was the son of the rector in Ryn and parish priest in Mikolajki Andreas Kowalewski (1669-1725), known as the "Prussian Job" - his wife and seven children died during the severe winter and plague epidemic of 1709. Celestyn Kowalewski began his studies at the Prussian University in Königsberg (Königsberg) in 1715. In 1733 he was appointed a councillor to the consistory. From 1735 to 1752 he was professor of pronunciation and history at Königsberg University, then professor of law and for four terms chancellor of his alma mater (1752-7171). He left the university library an impressive book collection of 2,500 volumes and a collection of paintings.

The epitaph from the Königsberg Cathedral is a flat slab of black compacted limestone with an inscription in Latin. It was originally decorated with the coat of arms of the Kowalewski family (Prussia III) crowning the monument, which was probably stolen. During the conservation work on the plaque, carried out by Andrzej Kazberuk, the coat of arms was reconstructed on the basis of a print with a portrait and the Kowalewski coat of arms found in the collection of the Herzog August Bibliothek in Wolfenbüttel .