Bydgoszcz

A city built on river trade

Casimir the Great granted Bydgoszcz its town charter on 19 April 1346. Its position on the Brda, near the river's junction with the Vistula, connected local commerce to a larger waterway. The city served the Kuyavian region, with merchants sending goods mainly northwards¹.

The mint: money for the Commonwealth

In 1594 Sigismund III Vasa authorized Stanisław Cikowski to establish a mint. An island in a bend of the Brda provided transport links and water power. Its products included three-grosz pieces, thalers, and ducats. During the Deluge the inactive mint was looted and damaged; production resumed in 1660 under Tomasz Tymf. Six-grosz pieces and złoty coins known as tymfs belong to this period².

Occupation and returning armies

Swedish forces occupied Bydgoszcz in August 1655. Stefan Czarniecki's troops recovered it in April 1656, but Swedish occupation resumed in May and continued until October. Looting, compulsory payments, and the destruction of buildings also affected inhabitants during subsequent operations³.

What happened to the castle?

An explosion during the Deluge destroyed the stronghold dating from Casimir the Great's reign in 1656. Its ruins were subsequently dismantled for building materials, with the last remains removed in the late nineteenth century. The castle's history therefore belongs to the area around Grodzka and Przy Zamczysku streets. The model displayed there is an attempted reconstruction, rather than an exact miniature: sufficiently precise plans have not survived to establish every detail⁴.

November 1657: signing and oath

The initial agreement was concluded at Wehlau on 19 September 1657. The final treaty was signed in Bydgoszcz on 5 November. The following day John Casimir and Elector Frederick William personally swore to its terms outside the Jesuit church. The elector joined an alliance against Sweden while gaining independence in Ducal Prussia. The Commonwealth secured a new ally at the cost of its feudal suzerainty. The Wehlau–Bydgoszcz treaty page explains the conditions and consequences⁵.

A church that no longer stands

The Jesuit church associated with the oath formed part of a larger complex beside the market square. Andrzej Kusztelski dates its construction to 1643–1648 and its consecration to 1653. Furnishings and college buildings continued to develop after the Deluge, so the complex had not reached its final appearance in 1657. The church and the oldest part of the college were demolished during the German occupation in 1940. The oath belongs to the history of a lost building, rather than the interior of a surviving church⁶.

Treasure beneath the floor

In January 2018 archaeologists discovered coins and valuables beneath the chancel floor of Bydgoszcz Cathedral. The jewellery includes objects dated to the first half of the seventeenth century. In 2024 the city presented a hypothesis linking the deposit to the starosta, Zygmunt Denhoff. This is a proposed interpretation, rather than a confirmed identification of its owner⁷.

The museum describes 486 gold coins, predominantly Dutch ducats and double ducats. It connects their presence to the circulation of money through the grain trade. The latest coins date from 1652, making that the earliest possible year of concealment. Neither the precise date nor the reason is known, however. A connection with the approaching Swedish invasion in 1655 remains a hypothesis. The find reveals both the city's wealth and the limits of what we can establish⁸.

A panorama worth reading critically

The earliest known view of Bydgoszcz is associated with Erik Dahlberg and the presence of Swedish troops in 1657. Its buildings and soldiers provide evidence of the period, but the engraving contains topographical errors. It must be read with attention to its military author's perspective and subsequent preparation for print⁹.

What survives, and what came later?

The European Money Centre at 4 Mennica Street connects the story of money with Mill Island's history. Its building, however, dates from the turn of the nineteenth century and probably occupies the site of one of the former mint buildings. It is not an intact mint surviving from the Deluge¹⁰.

Bydgoszcz struggled to recover after the Peace of Oliwa ended the war. Further destruction followed during the Great Northern War of 1700–1721. The Bydgoszcz Canal was built only after Poland's first partition; it was not part of the city's waterways in 1657. Our map marker identifies the city, rather than the precise location of the treaty signing or the hidden treasure¹.

Notes

1. Zdzisław Hojka; Zdzisław Biegański, Historia miasta, Bydgoszcz: Miasto Bydgoszcz, 2016
2. Mennica bydgoska, Bydgoszcz: Muzeum Okręgowe im. Leona Wyczółkowskiego w Bydgoszczy
3. Joanna Matyasik, Situs Oppidi Brombergae Erika Dahlberga – najstarsza panorama Bydgoszczy ze zbiorów Wojewódzkiej i Miejskiej Biblioteki Publicznej im. dr. W. Bełzy, Bibliotekarz Kujawsko-Pomorski, nr 1 (50), Bydgoszcz: Wojewódzka i Miejska Biblioteka Publiczna im. dr. Witolda Bełzy w Bydgoszczy, 2018, 32–42, pp. 35–37
4. Zamek w Bydgoszczy, Bydgoszcz: Bydgoski Serwis Turystyczny
5. Układy welawsko-bydgoskie, Oś czasu, Warszawa: Muzeum Wojska Polskiego w Warszawie
6. Andrzej Kusztelski, Zespół jezuicki w Bydgoszczy. Kształtowanie układu przestrzennego i architektura, Nasza Przeszłość, t. 113, Kraków: Nasza Przeszłość, 2010, 185–236, abstract
7. WW, Kolejna odsłona Skarbu Bydgoskiego, Bydgoszcz: Miasto Bydgoszcz, 2024
8. J. K., Skarb Bydgoski, Bydgoszcz: Muzeum Okręgowe im. Leona Wyczółkowskiego w Bydgoszczy, 2022
9. Joanna Matyasik, Situs Oppidi Brombergae Erika Dahlberga – najstarsza panorama Bydgoszczy ze zbiorów Wojewódzkiej i Miejskiej Biblioteki Publicznej im. dr. W. Bełzy, Bibliotekarz Kujawsko-Pomorski, nr 1 (50), Bydgoszcz: Wojewódzka i Miejska Biblioteka Publiczna im. dr. Witolda Bełzy w Bydgoszczy, 2018, 32–42, pp. 32–40
10. Europejskie Centrum Pieniądza, Bydgoszcz: Muzeum Okręgowe im. Leona Wyczółkowskiego w Bydgoszczy