<sod>At the same time when the [[Kingdom of Germany]] grew out of the German [[stem duchy|stem duchies]] of [[East Francia]] in the 10th century, the West Slavic [[Polans (western)|Polan]] tribes under the [[Piast dynasty|Piast]] prince [[Mieszko I of Poland|Mieszko I]] about 960 were able to establish a sovereign state around [[Poznań]] and [[Gniezno]] in an area later called [[Greater Poland]]. Mieszko significantly enlarged his territory by conquering [[Masovia]] beyond the [[Vistula]] river, the [[Silesia]]n in 962/63 he first met with the [[Duchy of Saxony|Saxon]] forces of Margrave [[Gero]], ruler of the ''[[Marca Geronis]]'' between the [[Saale]] and [[Bóbr]] rivers established in 937 by King [[Otto I, Holy Roman Emperor|Otto I of Germany]]. Gero defeated Mieszko I in 963 and forced him to recognize Otto I as his overlord.<ref>[[Timothy Reuter|Reuter]], 164. Howorth, 226.</ref> In return for submitting tribute to the newly crowned Emperor, Otto I granted Mieszko I the title of ''amicus imperatoris'' ("Friend of the Emperor") and acknowledged his position as ''dux Poloniae'' ("Duke of Poland"). As he could not prevail against Gero, Mieszko I resorted to consolidate his realm: he strengthened the relations with the Bohemian duke [[Boleslaus I, Duke of Bohemia|Boleslaus I]] by marrying his daughter [[Dobrawa of Bohemia|Dobrawa]] and converted to [[Christianity]] in 966. The next year however, he once again entangled with the troops of the Saxon renegade [[Wichmann the Younger]], fighting over the island of [[Wolin]] on the [[Baltic Sea|Baltic]] coast. He also had to defend the Polish border on the lower [[Oder]] river against the forces of Margrave [[Odo I, Margrave of the Saxon Ostmark|Odo I of Lusatia]] at the 972 [[Battle of Cedynia]].<eod>
<sod>In the 10th century, the West Slavic [[Polans (western)|Polan]] tribes under the [[Piast dynasty|Piast]] prince [[Mieszko I of Poland|Mieszko I]] about 960 were able to establish a sovereign state around [[Poznań]] and [[Gniezno]] in an area later called [[Greater Poland]]. Mieszko's territory included [[Masovia]] beyond the [[Vistula]] river, [[Silesia]] and in 962/63 he first met with the [[Duchy of Saxony|Saxon]] forces of Margrave [[Gero]], ruler of the ''[[Marca Geronis]]'' between the [[Saale]] and [[Bóbr]] rivers established in 937 by King [[Otto I, Holy Roman Emperor|Otto I of Germany]]. During the fight with Germanic duchies Mieszko I in 963 recognized Otto I as Emperor<ref>[[Timothy Reuter|Reuter]], 164. Howorth, 226.</ref> In return for tribute to the newly crowned Emperor, Otto I  reckognized Mieszko I as ''amicus imperatoris'' ("Friend of the Emperor") and stated that he is ''dux Poloniae'' ("Duke of Poland"). As he could not prevail against Gero, Mieszko I resorted to consolidate his realm: he strengthened the relations with the Bohemian duke [[Boleslaus I, Duke of Bohemia|Boleslaus I]] by marrying his daughter [[Dobrawa of Bohemia|Dobrawa]] and converted to [[Christianity]] in 966. The next year however, he once again entangled with the troops of the Saxon renegade [[Wichmann the Younger]], fighting over the island of [[Wolin]] on the [[Baltic Sea|Baltic]] coast. He also had to defend the Polish border on the lower [[Oder]] river against the forces of Margrave [[Odo I, Margrave of the Saxon Ostmark|Odo I of Lusatia]] at the 972 [[Battle of Cedynia]].<eod>