Mieszko I of Poland result of the conflict Silesia was taken over by Poland. However, the annexation of Silesia possibly took place around 985, because during this year the major Piast strongholds in Wrocław, Opole and Głogów were already being built. The issue of the incorporation of Lesser Poland is also not completely resolved. Possibly Mieszko took the region before 990, which is indicated by the vague remark of Thietmar, who wrote of a country taken by Mieszko from Boleslav. In light of this theory, the conquest of Lesser Poland could be a reason for the war, or its first stage. Many historians suggested
Mieszko I of Poland probably closer to the latter date. Due to the lack of sources it is not possible to determine exactly which lands he inherited. Certainly among them were the areas inhabited by the Polans and Goplans, as well as the Sieradz-Łęczyca lands and Kuyavia. It is possible that this state included also Masovia and Gdańsk Pomerania. Soon the new ruler had faced the task of integrating the relatively large, ethnically and culturally heterogeneous territory. Although the residents of areas controlled by Mieszko spoke mostly one language, had similar beliefs and reached a similar level of economic and general development, they were