Casimir II the Just

2.1. Birth and childhood

Casimir was born on 28 October 1138, potentially on the same day or shortly after the death of his father, Bolesław III Wrymouth, Duke of Poland. He was the sixth, but fourth surviving, son of Bolesław III by his second wife, Salomea of Berg, daughter of Count Henry of Berg. Due to his posthumous or near-posthumous birth, Casimir was notably omitted from his father's will, the Testament of Bolesław III Krzywousty, which meticulously divided the Polish lands among his other sons. This omission left Casimir without any land inheritance from his paternal patrimony.

During his early years, Casimir and his sister Agnes (born 1137) resided with their mother, Salomea, in her widow's land in Łęczyca. This period kept the young prince largely removed from the intense struggles between his older brothers, Bolesław IV the Curly and Mieszko III, and their elder half-brother, High Duke Władysław II, who attempted to reunite all of Poland under his sole rule, contrary to his father's testament. Władysław II was ultimately expelled in 1146.

2.2. Early struggles and political experiences

Casimir's mother, Salomea of Berg, died in 1144. Following her death, Casimir and Agnes were placed under the care of their elder brother, Bolesław IV, who assumed the high ducal title two years later. Despite being under Bolesław IV's tutelage, Casimir had no guarantee of receiving a portion of the family's inheritance in the future. By 1151, when he reached the age of 13, considered the proper age to assume control over lands, he still possessed nothing.

His situation further deteriorated in 1157 with the successful Polish campaign of Emperor Frederick Barbarossa, who intervened to support Władysław II and his sons. As part of the treaty Bolesław IV was forced to conclude with Barbarossa, Casimir was sent to Germany as a hostage to ensure his brother's loyalty to the Emperor. While the specifics of Casimir's time at the Imperial Court remain largely unknown, he certainly returned to Poland before 21 May 1161, as he is mentioned in a document on that date alongside his brothers Bolesław IV and Henry of Sandomierz. Despite his return, Casimir had yet to receive any land from his brothers.

3.1. Duke of Wiślica and Sandomierz

A significant turning point occurred in 1166 when Casimir's brother, Henry of Sandomierz, was killed in battle during a Prussian Crusade. Henry died without issue, and in his will, he named Casimir as the sole heir to his Lesser Polish Duchy of Sandomierz. However, High Duke Bolesław IV, in a move that angered Casimir, decided to partition the duchy into three parts. Bolesław IV took the largest portion, including the capital, Sandomierz, for himself. A second unnamed portion was granted to Mieszko III, while Casimir received only the smallest part, the district of Wiślica.

Incensed by this decision, Casimir rebelled against the High Duke. He garnered significant support, including that of his brother Mieszko III, the influential magnate Jaksa of Miechów, Sviatoslav (son of Piotr Włostowic), Archbishop Jan of Gniezno, and Bishop Gedko of Kraków. Casimir also enjoyed the backing of nearly all of Lesser Poland. However, swift actions by Bolesław IV suppressed the rebellion, and Casimir was only able to retain control of Wiślica. In 1172, Mieszko III rebelled against the High Duke once more, attempting to persuade Casimir to join him. For reasons that remain unclear, Casimir declined to participate in this second uprising.

The situation shifted decisively in 1173 with the death of Bolesław IV. According to the principle of agnatic seniority, his successor as High Duke was Mieszko III, the oldest surviving brother. Mieszko III then decided to grant the entire Sandomierz duchy to Casimir, who finally assumed the ducal title that his late brother, Henry, had intended for him.

3.2. Overthrowing Mieszko III and becoming High Duke

The strong and often dictatorial rule of the new High Duke, Mieszko III, generated deep dissatisfaction among the Lesser Polish nobility. This discontent culminated in a new revolt in 1177, which had a strong chance of success. The rebellion attracted support from influential magnates, Bishop Gedko of Kraków, Mieszko III's eldest son Odon, Bolesław I the Tall, Duke of Silesia (son of the former High Duke Władysław II), and Casimir himself. The precise reasons for Casimir's participation in this revolt, especially after his reconciliation with Mieszko III, are not fully known.

The power struggle took an unusual turn. Mieszko III, caught entirely by surprise by the rebels in his Duchy of Greater Poland, retreated to Poznań. He endured heavy fighting with his son Odon for nearly two years before being defeated and forced into exile. Meanwhile, Duke Bolesław I the Tall failed to conquer Kraków and the Seniorate Province. He was entangled in an internal Silesian conflict with his brother Mieszko I Tanglefoot and his own son Jarosław. Defeated in this conflict, Bolesław I the Tall sought assistance from Casimir. Following a successful intervention in Silesia, Casimir marched on Kraków, quickly securing control of the city. As the new Duke of Kraków, Casimir concluded a treaty granting Bolesław I the Tall full authority over Lower Silesia at Wrocław. In return, Casimir presented the Lesser Polish districts of Bytom, Oświęcim, and Pszczyna to the then-deposed Mieszko I Tanglefoot, as a gift for his godson and namesake, Casimir I of Opole, Mieszko I Tanglefoot's only son. With these actions, Casimir secured his position as High Duke of Poland.

4.1. Consolidation of power and the Łęczyca Assembly

The 1177 rebellion against High Duke Mieszko III was a decisive success for Casimir. He not only seized Kraków, including the districts of Sieradz and Łęczyca, thereby acquiring the high ducal title, but also extended his sovereignty as the Polish monarch over a broader territory. This included Silesia, which was then divided among the three sons of Władysław II (Bolesław the Tall, Mieszko I Tanglefoot, and Konrad Spindleshanks, as well as Bolesław's son Jarosław of Opole), Greater Poland (ruled by Odon), and Masovia and Kuyavia (ruled by Duke Leszek, who was still a minor and under the tutelage of his mother and the voivode Żyrona, one of Casimir's followers). On the Baltic Sea coast, Pomerelia (or Gdańsk Pomerania) was governed by Duke Sambor I as a Polish vassal, further acknowledging Casimir's suzerainty.

Despite Casimir's success, Mieszko III intensively worked towards his return from exile, seeking support first in Bohemia and later in Germany and the Duchy of Pomerania. To counteract these efforts and, more importantly, to establish the principle of hereditary succession for his descendants to the throne at Kraków (and thus the Seniorate Province), Casimir convened an assembly of Polish nobles at Łęczyca in 1180. During this significant gathering, he granted substantial privileges to both the nobility and the Church. He lifted a tax on the clergy's profits and relinquished his rights over the lands of deceased bishops. These strategic concessions aimed to secure the support of powerful factions and solidify his family's claim to the High Duchy, although it would take more than a century to fully restore the Polish kingship.

4.2. Internal conflicts and territorial changes

Despite the successes of the Łęczyca Assembly, Casimir's rule was continually challenged by internal conflicts, particularly with his persistent rival, Mieszko III. In the first half of 1181, less than a year after the Łęczyca assembly, Mieszko III, aided by Duke Sambor's brother Mestwin I of Pomerelia, managed to reconquer the eastern Greater Polish lands of Gniezno and Kalisz. Furthermore, Mieszko III successfully persuaded his son Odon to submit, with some historians suggesting that Odon then received from his father the Greater Polish lands south of the Obra River. Concurrently, Duke Leszek of Masovia decided to break away from Casimir's influence. He appointed Mieszko III's son, Mieszko the Younger, as governor of Masovia and Kuyavia, thereby tacitly promising the succession of these lands to Mieszko's lineage.

For unknown reasons, Casimir chose not to react to these developments concerning Gniezno, Kalisz, and Odon, instead focusing on securing his authority over Lesser Poland. In 1186, Duke Leszek of Masovia died. Despite having previously promised his inheritance to his elder uncle Mieszko III, the ailing duke had a change of heart due to Mieszko III's dictatorial methods and decided to bequeath all his lands to High Duke Casimir. However, shortly after Leszek's death, Mieszko III occupied the lands of Kuyavia up to the Vistula River, limiting Casimir's direct possession to Masovia proper. Nevertheless, the Masovian inheritance significantly expanded Casimir's direct rule over a major part of Poland.

The involvement of Casimir in Russian affairs in 1191 provided an opportunity for Mieszko III, who seized control of Wawel Castle at Kraków, reclaiming the high ducal title and control over the Seniorate Province. Mieszko III immediately declared Kraków an hereditary fief for his own descendants and installed his son Mieszko the Younger as governor. The conflict, however, concluded peacefully, as Casimir, upon his return from Russia, regained the capital without a fight, and Mieszko the Younger retreated to his father's side.

4.3. Foreign policy and interventions

Beyond the perpetual conflicts with his brother Mieszko III, the most significant aspect of Casimir's reign was his diplomatic engagement with the neighboring Kievan Rus' principalities to the east.

4.4. Relations with the Church

Throughout his reign, Casimir II demonstrated significant generosity and patronage towards the Catholic Church and various monastic orders, reflecting the profound social and religious influence of the era. He was particularly munificent to the Cistercian monasteries located in Wąchock, Jędrzejów, Koprzywnica, and Sulejów. Additionally, he extended his support to the Canons Regular of the Holy Sepulchre at Miechów, the Regular Canonry of Czerwińsk nad Wisłą and Trzemeszno, and the Order of the Knights Hospitaller in Zagość.

Casimir also actively supported the development of religious cults. Notably, he promoted the cult of Saint Florian, whose relics were brought to Kraków by Bishop Gedko. This patronage not only solidified his alliances with influential ecclesiastical figures but also contributed to the spiritual and cultural landscape of Poland under his rule.

4.5. Plans for a university

Demonstrating a forward-looking approach to education and societal development, Casimir II harbored ambitions to establish a university in Kraków. He initiated efforts and even began constructing a building for this purpose. However, his sudden death unexpectedly thwarted these progressive plans. The present-day Jagiellonian University, a renowned institution, was not founded until 1364 by King Casimir III the Great, making it the second oldest university in Central and Eastern Europe after the Charles University in Prague. Casimir II's early endeavors, though incomplete, highlight his vision for advancing learning within his realm.

5.1. Marriage and issue

Between 1160 and 1165, but certainly no later than 1166, Casimir married Helena of Znojmo (born around 1140/42 - died around 1202/06). Helena was the daughter of Duke Conrad II of Znojmo of Znojmo, a scion of a Moravian cadet branch of the Přemyslid dynasty. Together, Casimir and Helena had seven children:

• Maria** (renamed Anastasia after her marriage; born before 1167), married between 11 October and 24 December 1178 to Prince Vsevolod IV of Kiev. Through Maria's great-granddaughter, Kunigunda of Slavonia, Casimir was a direct ancestor of the last Přemyslid Kings of Bohemia and the Holy Roman Emperors of the Luxembourg dynasty.
• Casimir** (born around 1162 - died 2 February or 1 March 1167), named after his father.
• Bolesław** (born around 1168/71 - died 16 April 1182/83), likely named after his paternal grandfather, Bolesław III Wrymouth, or perhaps in honor of his uncle, Bolesław IV the Curly. He died accidentally after falling from a tree and was likely buried at Wawel Cathedral.
• Odon** (born 1169/84 - died in infancy). He was probably named after either Odon of Poznań or Saint Odo of Cluny.
• Adelaide of Poland|Adelaide** (born around 1177/84 - died 8 December 1211), who became the foundress of the convent of St. Jakob in Sandomierz.
• Leszek I the White** (born around 1184/85 - died 24 November 1227). He succeeded his father as High Duke of Poland.
• Konrad I of Masovia|Konrad** (born around 1187/88 - died 31 August 1247). He later became Duke of Masovia.

5.2. Ancestry

Casimir II the Just was a member of the Piast dynasty, with a lineage extending through several prominent European noble houses:

7.1. The "Just" appellation

The honorific title "the Just" (Sprawiedliwy^Polish) was not a contemporary appellation during Casimir II's lifetime. This epithet first appeared in the 16th century, centuries after his death. Its emergence reflects a later historical assessment of his rule, suggesting that he was perceived as a fair and equitable ruler, especially in contrast to his more dictatorial brother, Mieszko III.

7.2. Contributions and influence

Casimir II played a crucial role in Polish history, notably as the progenitor of the Masovian branch of the Piast dynasty. His descendants, including his great-grandson, the later Polish king Władysław I the Elbow-high, significantly influenced the political landscape of medieval Poland.

His most significant contribution lay in his efforts to stabilize the Seniorate Province and strengthen the position of the High Duke within the fragmented realm. Through his diplomatic maneuvers, military interventions, and strategic alliances, such as with the Holy Roman Emperor, Casimir sought to curb the centrifugal forces unleashed by Bolesław III's testament. The Łęczyca Assembly of 1180, where he granted privileges to the nobility and the Church and sought to establish the principle of hereditary succession to Kraków, underscores his long-term vision for a more unified and stable Polish state, even if the full restoration of the Polish kingship would not occur for more than a century after his death. His plans for a university in Kraków also demonstrate a forward-thinking approach to societal and cultural development. Despite facing continuous internal conflicts, particularly with Mieszko III, Casimir's reign is often viewed positively for contributing to the re-establishment of a more centralized ducal authority and laying some groundwork for future Polish statehood.