The first settlers were probably from the Celtic tribes. In later years they
were driven out by the Slavic population. The importance of mining deposits
arose after the capital of Poland was moved from Gniezno to Kraków by Casimir I
the Restorer. Brewing brought huge revenues, which the prince needed to
maintain the court and rebuild the destroyed country. Systematic development of
the mining settlement stopped the Tartar invasion, which destroyed Kraków and
surroundings.
After the 1252 discovery of salt and potassium deposits extraction of salt
from deep regions in the earth began. In the year 1289, Henryk IV
