The rise of medieval towns was not only significant because it was a source of growth in Europe, but it was a source of freedom as well.
Any serf, a slave to a lord, who was able to hide from his master in a town for a year and a day would be free and not obligated to serve the lord any longer. The lord who owned the land on which a town was located gave his consent to the development of a town because he could tax the people living there, therefore gaining income. But taxation could only go to a certain extent because if taxes were too high people would leave, leaving the lord with fewer tax payers and less income.
These towns were the beginning of the development of self government. Over time the towns began to gain more and more liberties from the lord, eventually being able to choose their own officials.