In the Early Middle Ages, a Slavic stronghold was built in present-day Koronowo. It was included into the emerging Polish state in the 10th century and finally integrated with it in the 12th century. In 1288 the Cistercians from nearby Byszewo founded an abbey in Koronowo. The settlement prospered due to its location at the intersection of trade routes from Kuyavia and Greater Poland to Gdańsk, and from the Chełmno Land to Western Pomerania. In 1359 King Casimir III the Great vested it with town privileges, which however were not implemented until 1370. The name Koronowo comes from the word "korona" ("crown"). Administratively it was located within the Inowrocław Voivodeship in the Greater Poland Province of the Polish Crown. A significant battle took place nearby in 1410 during the Polish–Lithuanian–Teutonic War, in which Poland defeated the Teutonic Knights.