January 1, 1039
Return of Casimir the Restorer to the Polish throne
In 1039, Casimir I the Restorer, son of Mieszko II and Richeza, returned from exile to Poland, beginning the process of rebuilding and unifying the state after a period of deep crisis. Supported by Emperor Henry III and Kievan Rus, he gradually regained control over Lesser Poland, Greater Poland, Masovia, and Silesia. His reign brought stability to the country through administrative, economic, and ecclesiastical reforms.