Koło received its foundation charter on 18 July 1362. It allowed Henryk, a former alderman in Warta, to found the city in accordance with the norms of the Magdeburg Law, on the area of the current Koło village. Originally a village, then a town, it was located on an island on the Warta River. Outside the town limits, a stone Gothic fortified castle was built.
Until the end of the 18th century, the town remained a royal property. In 1409, the parish church was built and consecrated. In 1554, a new town called Zduny was founded to the north-east of the town, on the right bank of the Warta River, on the area of the previous Toruń Outskirts. In 1559, it received the privilege to have its own government. Koło was known in former Poland because the General Sejmiks of Greater Poland Province gathered there from 1433 to 1716. The meetings held by the gentry created favorable conditions for the town to develop, especially trade and craft. Pottery played a particularly important role. In 1620, ten potters, two carpenters, a blacksmith, two dry-goods merchants and two tailors worked in Zduny.
Together with geopolitical changes, the role of Koło castle decreased. From the 16th century it gradually fell into decline and now only small fragments of the castle remain. The 17th century initiated the gradual collapse of Koło. In 1622, the Polish army coming back from the war in Hungary burnt the town. In 1655, Swedish troops occupied the town and burnt it to the ground. In 1658, Koło had 142 houses.
At the end of the 18th century, the number of houses decreased to 101, only three were of stone. The streets were cobbled and there were two bridges crossing the Warta River. People worked mainly in trade, crafts, farming and breeding. Among the craftsmen, there were ten shoemakers, ten potters, nine furriers, eight butchers. Also, two water mills were in operation. In the 19th century, the first industrial enterprises appeared.
At the end of the century three factories were producing faience, there were factories making agricultural implements, cotton goods, narrow tapes and bone meal. Moreover, there were a brewery, mill, brickyard and sawmill. Craftsmen specialized in shoemaking, tailoring and carpentry. After World War II, Koło underwent a process of intense industrialization. The former pottery factories were extended; meat and mineral industries were developed. Nowadays, the town functions as the local industrial, trading, service and cultural center.
Józef Stanisław Mujta, Koło w dokumentach, Koło-Konin 1998; Sześćset lat miasta Koła. Praca zbiorowa pod red. Józefa Burszty, Poznań 1963.