Casimir II the Just in the context of "Władysław I the Elbow-high"

Casimir I of Kuyavia (Polish: Kazimierz I kujawski; c. 1211 – 14 December 1267) was a Polish prince and a member of the House of Piast. He was Duke of Kujawy after 1233, ruler over Ląd from 1239-1261, ruler over Wyszogród after 1242, Duke of Sieradz from 1247-1261, Duke of Łęczyca after 1247, and Duke of Dobrzyń after 1248.

He was the second son of Konrad I of Masovia and his wife Agafia of Rus. He was probably named after his grandfather, Casimir II the Just.

The Duchy of Wiślica was a district principality and a fiefdom within the Kingdom of Poland. It was formed in 1166 from the territories of the Duchy of Sandomierz, following its fragmentation onto three parts. The state was ruled by Casimir II the Just, and it existed until 1173, when Casimir had assumed the throne of the Duchy of Sandomierz, uniting two states together. Its capital was Wiślica and it was located in the southern Sandomierz Land in the southeastern corner of the Kingdom of Poland. The state was later shortly reestablished in 1230 by Grzymisława of Łuck who ruled it as a regent in the name of her son, Bolesław V the Chaste. In 1234, they had become rulers of the whole Duchy of Sandomierz, with that year being the last mention of the duchy in the documents.

Leszek of Masovia (Polish: Leszek, also Lestek; b. ca. 1162 - d. 1186) was a Polish prince from the Piast dynasty, the Duke of Masovia from 1173 until his death. He was the only son of Bolesław IV the Curly, Duke of Masovia and High Prince of Poland, to survive his father. After his father's death he inherited Masovia. At the beginning, Leszek ruled under the guardianship of his uncle Casimir II the Just. He was a man of poor health. For a short time he supported his other uncle, Mieszko III the Old, but later decided to reconcile with Casimir II, who after Leszek's death inherited his duchy.

The Duchy of Kalisz was a feudal district duchy in Greater Poland, with its territorial and administrative core in the Kalisz Land — the region surrounding the city of Kalisz. Its capital was Kalisz. The duchy was established in 1177, following the partition of the Duchy of Greater Poland after a rebellion against Mieszko III. Duke Casimir II the Just of the Piast dynasty became its first ruler.

Initially, Kalisz remained a fiefdom within the broader Duchy of Poland — a term commonly applied to the fragmented realm, which some sources continue to refer to as the Kingdom of Poland — until 1227, when Kalisz gained independence as a duchy. It existed in this form until 1279, when it was united with the duchies of Gniezno and Poznań under the rule of Przemysł II, forming a reconstituted Duchy of Greater Poland.

The Duchy of Bytom (Polish: Księstwo Bytomskie, Czech: Bytomské knížectví, German: Herzogtum Beuthen) was a duchy in Upper Silesia, one of the Silesian duchies of fragmented Piast-ruled Poland. It was established in Upper Silesia about 1281 during the division of the Duchy of Opole and Racibórz among the sons of Duke Władysław Opolski. The duchy's capital was Bytom, formerly part of Lesser Poland until in 1177 the Polish High Duke Casimir II the Just had attached it to the Silesian Duchy of Racibórz.

The Duchy of Gniezno was a feudal district duchy in Greater Poland, with its territorial and administrative core in the Gniezno Land — the region surrounding the city of Gniezno. Its capital was Gniezno. The duchy was established in 1177, following the partition of the Duchy of Greater Poland after a rebellion against Mieszko III. Duke Casimir II the Just of the Piast dynasty became its first ruler.

Initially, Gniezno remained a fiefdom within the broader Duchy of Poland — a term commonly applied to the fragmented realm, which some sources continue to refer to as the Kingdom of Poland — until 1227, when Gniezno gained independence as a duchy. It existed in this form until 1279, when it was united with the duchies of Kalisz and Poznań under the rule of Przemysł II, forming a reconstituted Duchy of Greater Poland.