Boleslaw I's intervention in the Kievan succession crisis, 1018, a Polish intervention into who would be ruler of Kiev and the state of Kievan Rus'
Boleslaw Ocias | Boleslaw I's intervention in the Kievan succession crisis, 1018 | Boleslaw I |
By conquest the first leaders of the Polans, Mieszko I and especially Boleslaw I added a number of surrounding territories to the newly established core Polish state, and Lebus Land or Lubusz in Lusatia came under Polish rule.