Duchy of Gniezno

The Duchy of Gniezno was a feudal district duchy in the Greater Poland, centered on the Kalisz Region. Its capital was Gniezno. The state was established in 1177, in the partition of the Duchy of Greater Poland, after the rebellion against Mieszko III. Duke Casimir II the Just of the Piast dynasty become its first ruler. It existed until 1279, when, it got united with duchies of Kalisz and Poznań, under the rule of Przemysł II, forming the Duchy of Greater Poland. It remained a fiefdom within the Duchy of Poland, until 1227, and after that, it become an independent state.