Hieronim Radziejowski (1612—August 8, 1667) was a Polish noble, politician, diplomat, scholar and a military commander. He was the governor of Sochaczew since 1643 and Vice-Chancellor of the Crown between 1650 and 1652. He also served as Marshal of the Sejm on November 13 – March 27, 1645 in Warsaw. He came into conflict with King John II Casimir when he found out that his wife, Elżbieta Słuszka was the King's mistress. Radziejowski started to conspire against the King with the enemies, and as a result was sentenced to infamy and banishment (exile) in 1652 by the Sejm Tribunal. He left Poland for Sweden, and convinced the Swedish to attack the Commonwealth. In 1655, Radziejowski accompanied the Swedish forces during their invasion of Poland in the course of The Deluge. He played an important role in persuading the militia (pospolite ruszenie) to surrender at Ujście. In 1662 he was pardoned by the Sejm. In 1667 he went on a diplomatic mission to the Ottoman Empire and died there. He was the father of Michał Stefan Radziejowski. Early political career At the beginning of the seventeenth century he arrived at the court of King Władysław IV, where he quickly gained considerable influence, and most notably was appointed the starost of Sochaczew. In 1640, for the first time, he became a senator in the Sejm (parliament) despite a scandal (before the meeting of the parliament he was accused of rape). In 1645 he was appointed Speaker of the Chamber of Deputies. Afterwards, on behalf of the king, he was involved in secret negotiations with the Cossacks for their support of Poland in an expedition against the Turks. However in 1646, when the secret negotiations became public, the nobles and senators of the Sejm, opposed the campaign. At the same time Radziejowski gained influence at the court of the queen, appearing at the same parliament session to defend her royal interests. In 1648 he participated in the Battle of Piławce. Radziejowski was one of the noblemen accused of contributing to the escape of the Polish army during that battle. He then campaigned for the election of John II Casimir and supported his marriage to the widow of Władysław IV, Queen Marie Louise Gonzaga. In 1648 he was the elector of John II Casimir representing the city of Łomża. In May 1650, he married (his two previous wives died) the newly widowed Elżbieta Służka,