The castle in Brześć Kujawski erected probably king Casimir the Great within the city walls in the southwestern corner of the town, although it is possible that the first fortification works could still begin during the reign of Władysław I the Elbow-high, when the settlement was moved from the village of Stary Brześć to a new place. The brick castle was probably built after 1346, when the Kuyavian land permanently returned to the Kingdom of Poland.
From the time of Casimir the Great, the castle was the seat of starosts, whose jurisdiction in the fourteenth century covered the whole of Kuyavia. In the fourteenth and fifteenth centuries it was an important resistance point on the border with the Teutonic state. It was often visited by Polish kings, especially Władysław Jagiełło, who visited Brześć 26 times from 1399 to 1430, both in connection with the round of the kingdom and in connection with the war operations. In the 16th century, Zygmunt the Old also visited the castle many times, although starting from the second half of the 15th century due to poor management by the starosts residing in it, castle began to decline. The greatest negligence was caused by the long-term rule of the starost Mikołaj of Brudzewo from 1455 – 1494. Major renovations were carried out only in the mid-16th century by the starost Sebastian Mielecki, who, among others, rebuilt the main castle house and smaller buildings along the eastern curtain of the defensive wall. The castle was burnt down by the Swedes in the 17th century, the inspection from 1644 showed only the burned walls. It was demolished in the early nineteenth century.
The castle was built on the right bank of the Zgłowiączka river, on the southern edge of the area elevated over 10 meters. From the north, that is, from the town side, there were outer bailey, separated by a ditch, through which the road to the main castle led. So it was linked to the town, but at the same time it was an autonomous defensive work, because it was separated from Brześć by a ditch 23-24 meters wide. The whole town and castle complex was also surrounded by a second moat forming the outer defense line. It is known that in the 16th century the outer bailey was surrounded by a wooden fence within which a half-timbered stable and a equerry ‘s house were located.
It is known that the castle was built of bricks laid in a Flemish bond, tied with lime mortar and set on a stone foundation. Based on historical plans, it can be assumed that it had the shape of a polygon measuring 40 x 47 meters closed on all sides by a perimeter wall about 7 meters high, while the city defensive wall circled the castle promontory a bit wider, constituting from the outside the second line of castle fortifications. The only entrance to the castle probably led from the north and the adjacent main castle house was located from this side. Its dimensions were 12 x 23.5 meters. It is not certain what the gate looked like in the Middle Ages, perhaps it was similar to the building known from the 16th century descriptions, when the gatehouse was a brick, two-storey building with a hal-timber superstructure or a foregate. In the south-eastern corner stood a cylindrical tower with a diameter of about 6.5 meters, while the southern and western part of the courtyard was occupied by economic buidlings attached to the inner faces of the perimeter walls. Also associated with the castle was the chapel mentioned for the first time in 1436.
The main castle building has been preserved to this day, which, however, as a result of a thorough rebuilding completely lost its original features. Currently, it is used by the Post Office and the library.
Leksykon zamków w Polsce, L.Kajzer, S.Kołodziejski, J.Salm, Warszawa 2003.
Pietrzak J., Zamki i dwory obronne w dobrach państwowych prowincji wielkopolskiej, Łódź 2003.
Widawski J., Miejskie mury obronne w państwie polskim do początku XV wieku, Warszawa 1973.