According to legend, the city was founded by two brothers, Byd and Gost, who wandered from southern Poland towards the north looking for the best possible location for their town. Eventually, they found an ideal place, with a river, a ford, some hills nearby and roads running to all four sides of the world.
Originally, the town was a stronghold defending the borderline of Masovian Duchy, first from pagan Prussians and later from Teutonic Knights. In the 13th century, Bydgoszcz was conquered by the Order, but in the following century it was returned to Poland and granted municipal rights by King Casimir the Great.
Soon, the construction of the castle at the bank of Brda River started. From the 15th century on, Bydgoszcz dynamically developed, extending its area and absorbing the neighbouring villages. Several granaries that can still be seen in Bydgoszcz are the traces of that great commercial prosperity.
Bad times came with the Swedish attacks in the mid-17th century. The castle was destroyed, never to be rebuilt. In 1772, as a result of the first partition of Poland, Bydgoszcz was incorporated by Prussia and renamed Bromberg. It was the Prussians who constructed the Bydgoszcz Canal at the end of the 18th century, making Bydgoszcz an important inland port and boosting its development as a place of trade.
After a short period within the borders of Duchy of Warsaw, established by Napoleon in 1807, the city was returned to Prussia in 1815. The 19th century saw not only a strong Germanisation of the citizens, but also the growing importance of Bromberg on the economic map of Prussia. In 1851, it was connected directly with Berlin by railway.
Bydgoszcz reappeared within the borders of Poland after World War I and the Greater Poland Uprising, in which the locals took an active part. Twenty years later, German troops entered the city, their pretext being the Bromberg Bloody Sunday incident, a conflict in Bydgoszcz reputedly started by Poles.
The local inhabitants seriously suffered during World War II, and about one-fourth of them were killed. In 1945, the Red Army liberated the city. Since then, it has returned to normal life, constantly developing and beautifying itself.