Mieszko I of Poland the conspiracy against Otto II was documented in only one source, the chronicles of the monastery in Altaich in its entry for the year 974. The Duke of Bavaria was defeated, and Emperor Otto II regained full power. Shortly afterwards, the young emperor waged a retaliatory expedition against Bohemia, in 978 forcing Duke Boleslav into submission. In 977 Mieszko's wife, Dobrawa, died. At first there were no apparent repercussions, as the Polish ruler had maintained his alliance with Bohemia. In 979 Otto II supposedly attacked Poland. Mention of this event can be found in the "Chronicle of the Bishops of
Mieszko I of Poland the Polabian Slavs. On the other hand, the supporters of the Gero's invasion theory believe that the Margrave did actually carry out a successful invasion, as a result of which Mieszko I was forced to pay tribute to the Emperor and also was compelled to adopt Catholicism through the German Church. The thesis that proposes the introduction of Catholicism as a result of this war finds no confirmation in German sources. The homage is then a separate issue, since, according to the chronicle of Thietmar, Mieszko actually paid tribute to the Emperor from the lands "usque in Vurta fluvium" (up