This is a list of alliances made by the Polish leaders during the Middle Ages (formation to 15th century).

Mieszko I

Otto II, Holy Roman Emperor (marriage with the German Oda)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.11

Boleslaus I the Cruel of Bohemia (later marriage with his daughter, Doubravka)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.11

Henry II Quarrelsome, Duke of Bavaria (support in war over Holy Roman throne)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.14

Otto III, Holy Roman Emperor (took part in a meeting at Quedlinburg, helped in war against Brandenburg)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.18

Bolesław Chrobry

Otto III, Holy Roman Emperor (helped in war against Obotrites)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.19

Sviatopolk I the Accursed of Kiev (put on throne by Bolesław)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.12

Henry II, Holy Roman Emperor (result of peace treaty, later marriage of Bolesław's son with Richeza of Lotharingia)'Ilustrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.24

Pechenegs (received help in war against the Kievan Rus')

Moravia (former Greater Moravia) (received help in war against Germans and Czechs)

Saint Stephen I of Hungary (received help in war against Kievan Rus')

Mieszko II Lambert/Gnuśny

Saint Stephen I of Hungary (received help in war against Germans and Czechs)

Bezprym

Conrad II, Holy Roman Emperor (part of coalition)

Yaroslav I the Wise (part of coalition)

Kazimierz I Odnowiciel

Yaroslav I the Wise (strengthened by marriage with his sister, Maria Dobroniega)

Bolesław II Szczodry

Béla I the Champion/Wisest of Hungary (supported throne)

Géza I of Hungary (supported throne)

Sweyn II Estridsson of Denmark (supported in a raid against British tribes)

Saxons (supported rebellion)

Bolesław III Krzywousty

Kievan Rus' nobles (received help in war against Czechs) 'Ilusrowane dzieje Polski'. Wydawnictwo Olesiejuk, 2015, p.39

References