History of Poland during the Piast dynasty of Lesser Poland, the country of the Vistulans, and of Silesia (both taken by Mieszko from the Czech state during the later part of the 10th century), Mieszko's state reached its mature form, including the main regions regarded as ethnically Polish. The Piast lands totaled about in area, with an approximate population of under one million. Initially a pagan, Mieszko I was the first ruler of the Polans tribal union known from contemporary written sources. A detailed account of aspects of Mieszko's early reign was given by Ibrâhîm ibn Ya`qûb, a Jewish traveler, according to whom Mieszko was one of
Bolesław the Forgotten calendar was in use so New Year's Day had not been changed to the first day of January. The text describes him as follows: However, there is no mention of any coronation of a Polish ruler in this period, which would have to be recorded in the German sources (as was the case with the coronations of Bolesław I and Mieszko II), probably because there was no royal insignia in the country, which had been returned to the Emperor by the well-known Bezprym earlier in the year 1031. This brief description of Bolesław in the "Wielkopolska Chronicle" is very similar