Geography of Poland today's modern Polish society. The ancestors of today's Poles, the Polanie, built their first fortresses on islands in these lakes. The legendary Prince Popiel ruled from Kruszwica tower erected on the Lake Gopło. The first historically documented ruler of Poland, Duke Mieszko I, had his palace on an island in the Warta River in Poznań. Nowadays the Polish lakes provide a location for the pursuit of water sports such as yachting and wind-surfing. The Polish Baltic coast is approximately long and extends from Świnoujście on the islands of Usedom and Wolin in the west to Krynica Morska on the Vistula
Mieszko I of Poland Polish take-over. Possibly the Wolinians themselves called the Margrave and asked his help. In any event, Odo's forces moved in and on 24 June 972 twice engaged Mieszko's army at the village of "Cidini", commonly identified with Cedynia. At first, the Margrave defeated Mieszko's forces; subsequently the Duke's brother Czcibor defeated the Germans in the decisive stage, inflicting great losses among their troops. It may be that Mieszko intentionally staged the retreat, which was followed by a surprise attack on the flank of the German pursuing troops. After this battle, Mieszko and Odo were called to the Imperial Diet in