European city boom
The 13th century was the time of the development of crafts, trade and farming in Western Europe, which allowed the inhabitants of many cities and villages to enjoy prosperity. However, over time, the population growth resulted in many craftsmen, merchants and peasants travelling abroad to seek fortune.
At the same time, when Poland was suffering from fragmentation, another problem arose. Although dukes and bishops owned plenty of ploughland, they lacked people who could farm it.
Thus, these two powers shared a similar need. Silesian dukes had been inviting German settlers to their lands already at the beginning of the 13th century. Thanks to them dozens of new cities such as Wrocław and Opole emerged in Silesia. They brought profit for both their founders as well as inhabitants.
The idea proved to be successful. Soon the rulers of the Wielkopolska Region followed suit. It is possible that the agents in this process were princesses from the Piast dynasty, many of whom were of German and Silesian descent. For instance, it was Silesia that Elżbieta Wrocławska, the wife of Poznań’s founder, Duke Przemysł I, came from.
Cities founded under the German law (e.g. the Magdeburg Law) in the 13th century