Mieszko II Lambert (Polish pronunciation: [ˈmjɛʂkɔ ˈdruɡʲi ˈlambɛrt] ; c. 990 – 10/11 May 1034) was King of Poland from 1025 to 1031 and Duke from 1032 until his death.
He was the second son of Bolesław I the Brave but the eldest born from his third wife, Emnilda of Lusatia. He organized two devastating invasions of Saxony in 1028 and 1030. Then, he ran a defensive war against Germany, Bohemia and the Kievan princes. Mieszko II was forced to escape from the country in 1031 after an attack by Yaroslav I the Wise, who installed Mieszko's older half-brother Bezprym on the Polish throne. Mieszko II took refuge in Bohemia, where he was imprisoned by Duke Oldrich. In 1032, he regained power in one of Poland's three districts, then united the country, making good use of the remaining power structures. At this time, several Polish territorial acquisitions of his father were lost: Upper Lusatia (also known as Milsko), part of Lower Lusatia, Red Ruthenia, the western and central parts of Upper Hungary (now Slovakia) and probably Moravia.
Mieszko II was very well educated for the period. He was able to read and write and knew both Greek and Latin. He is unjustly known as Mieszko II Gnuśny (the "Lazy", "Stagnant" or "Slothful"). He received that epithet due to the unfortunate way his reign ended, but in the beginning, he acted as a skillful and talented ruler.
Mieszko was a son of King Bolesław the Brave. He was probably named after his paternal grandfather, Mieszko I. His second name, Lambert, sometimes erroneously considered to be a sobriquet, was given to him as a reference to Saint Lambert. However, it is also probable that the name was chosen after Bolesław's half-brother Lambert Mieszkowic. It is thought that the choice of this name for his son was an expression of warming relations between Bolesław I and his stepmother Oda of Haldensleben.
Since Mieszko II was politically active before his father's death, Bolesław appointed him as his successor. He participated mainly in German politics, both as a representative of his father and the commander of the Polish troops.
In 1013, Mieszko II went to Magdeburg, where he paid homage to Emperor Henry II. A few months later, Bolesław I paid homage in person. The real purpose of Mieszko II's visit is unclear, especially since soon afterwards, his father paid homage to the Holy Roman Empire. Presumably, the young prince paid homage to Milsko, Lusatia and Moravia. The relevant treaty stipulated that it was only a personal tribute, not entailing any legal obligations. Another hypothesis assumes that the territories were transferred by Bolesław to him, and as a result, made Mieszko II a vassal of the Empire.
The position of the young prince, at both the Polish and Imperial courts, became stronger in 1013 when he married Richeza, daughter of Count Palatine Ezzo of Lotharingia and niece of Emperor Otto III. Ezzo was a prince of considerable influence as a great leader of the opposition against Henry II. Through marriage with his daughter, Mieszko II entered the circle of the Imperial family. Probably after the wedding, and in accordance with prevailing custom, Bolesław I the Brave gave a separate district to Mieszko II to rule: Kraków. One of his towns, Wawel (now part of the city), was chosen by the prince as his residence.
In the year 1014, Mieszko II was sent by his father to Bohemia as an emissary. He had to persuade Duke Oldřich to make an alliance against Emperor Henry II. The mission failed as Oldřich imprisoned Mieszko II. He was released only after the intervention of the Emperor, who, despite the planned betrayal of Bolesław I, loyally acted on behalf of his vassal. As a result, Mieszko II was sent to the Imperial court in Merseburg as a hostage. Henry II probably wanted to force the presence of Bolesław I in Merseburg and make him explain his actions. The plan failed, however, because, under pressure from his relatives, the Emperor soon agreed to release Mieszko II.
A year later, Mieszko II stood at the head of Polish troops in the next war against the Emperor. The campaign was not favorable to Henry. His army needed over a month to reach the line of the Oder River, and once there, his troops encountered strong resistance led by Mieszko II and his father. Henry II sent a delegation to the Polish rulers in an effort to induce them to conclude a peace settlement. Mieszko II refused, and after the Emperor's failure to defeat his troops in battle, Henry decided to begin retreating to Dziadoszyce. The Polish prince went in pursuit and inflicted heavy losses on the German army. When the Polish army advanced to Meissen, Mieszko II unsuccessfully tried to besiege the castle of his brother-in-law, Margrave Herman I (husband of his sister Regelinda). The fighting stopped in autumn and was resumed only in 1017 after the failure of peace talks. Imperial forces bypassed the main defensive site near Krosno Odrzańskie and besieged Niemcza. At the same time, at the head of ten legions, Mieszko II went to Moravia and planned an allied attack together with Bohemia against the Emperor. This action forced the Emperor to give up on any plan of a frontal attack. A year later, the Peace of Bautzen (30 January 1018) was concluded, with terms extremely favorable to the Polish side.
Beginning in 1028, Mieszko II successfully waged war against the Holy Roman Empire. He was able to repel its invading army, and later even invaded Saxony. He allied Poland with Hungary, resulting in a temporary Hungarian occupation of Vienna. This war was probably prompted by family connections of Mieszko II's in Germany, who opposed Emperor Conrad II.
Due to the death of Thietmar of Merseburg, the principal chronicler of that period, there is little information about Mieszko II's life from 1018 until 1025, when he finally took over the government of Poland. Only Gallus Anonymus mentions the then Prince on the occasion of the description of his father's trip to Rus in 1018: "due to the fact that his son (...) Mieszko wasn't considered yet capable of taking the government by himself, he established a regent among his family during his trip to Rus". This statement was probably the result of the complete ignorance of the chronicler, since in 1018, Mieszko II was 28 years old and was already fully able to exercise power by himself.
King Bolesław died on 17 June 1025. Six months later, on Christmas Day, Mieszko II Lambert was crowned king of Poland by the archbishop of Gniezno, Hipolit, in the Gniezno Cathedral. Contemporary German chroniclers considered this to be an abuse of power on the part of the Archbishop, which was made necessary by the existing political situation. After his father's death, Mieszko II inherited a vast territory, which in addition to Greater Poland, Lesser Poland, Silesia and Gdańsk Pomerania, also included Lusatia, Red Ruthenia and the territory of present-day Slovakia. Whether Moravia was still under his reign or was lost earlier is disputed. Once his solo reign had begun, as an important Central European ruler, he was now very important to the Holy Roman Empire.
Later developments during his reign had their source in dynastic and familial issues. His older half-brother Bezprym was the son of the Hungarian princess Judith, Bolesław's second wife. Mieszko II also had a younger full-brother, Otto. According to Slavic custom, a father was expected to divide his legacy among all his sons. However, since Bolesław I did not wish to break up the kingdom, Mieszko II's brothers received nothing from their father's legacy.
As Bezprym was the oldest son, there were some who felt that he should have succeeded his father as king. Bezprym had, however, always been disliked by his father, as indicated by his name (the Piasts tended to give names such as Bolesław, Mieszko and later Kazimierz, Władysław and emperors' names, such as Otto, Konrad (Conrad), and Henryk (Heinrich). Bezprym was rather a commoner's name, which implied that Bolesław did not wish Bezprym to succeed him). For that reason, Bezprym was sent to a monastery.