In the Battle of Cedynia or Zehden, an army of Mieszko I of Poland defeated forces of Hodo or Odo I of Lusatia on 24 June 972, near the Oder river. Whether or not the battle actually took place near the modern-day town of Cedynia is disputed in modern scholarship.Mieszko I, Poland's first documented ruler based in Greater Poland, had successfully campaigned in the Cedynia area, then a West Slavic tribal territory also coveted by Holy Roman Emperor Otto I and German nobles. While Mieszko's differences with Otto I were settled by an alliance and payment of tribute to the latter, the nobles whom Otto I had invested with the former Saxon Eastern March, most notably Odo I, challenged Mieszko's gains. The battle was to determine the possession of the area between Mieszko and Odo. Records of the battle are sparse, it was briefly described by the chronicler Thietmar of Merseburg (975−1018), whose father participated in the battle (Chronicon II.19).