The serf rolls (in German Mannschaftsbücher) were records of all hereditary serfs, which were annually compiled from the second half of the 17th century by the seigniorial offices in a number of Czech estates. They served to keep tabs on the serfs - recording their whereabouts and their fulfilment of obligations to the nobility. The records contained notes on the place of residence and changes in the life of the persons registered in them (e. g. if they left to enter into service or to become an apprentice, if they married or took over a piece of land, and when they died). Although one of the purposes of the serf rolls was to monitor the mobility of serfs, their usefulness for studying migration is limited. The rolls did not consistently record the whereabouts of people outside their place of residence, and people who were not serfs subordinate to the local manor were not recorded in the documentation. The study of migration using the serf rolls must therefore be narrowed to the question of how much of a role migration played in the formation of the age and gender structure of the population in specific localities. A study of four localities in Horní Police in 1710-1725 confirmed that people most often migrated at the age of 20-35 years. People of that age left home most often for the purpose of marriage. Typical for people over 35 years of age was the tendency to remain in one place, and typical for people over 50 years of age was their elimination from the records of the serf rolls, almost exclusively as a result of their death. Children up to the age of 15 tended to move with their parents.