In the following passage Pope Pius II describes Vienna, circa 1458. This portrait of urban life is excerpted from a work titled The History of Emperor Frederick III, which was published in 1669. Although Vienna's walls, architecture, churches, and markets impress Pius, aspects of the city's social life trouble him. "He also notes how many of Vienna's residents are new to the city, reflecting the general trend toward urbanization. An old proverb, "city air makes one free," referred to the custom which granted liberty and citizenship to former serfs who spent a year and a day within a city's walls. Based on Pius' account, this custom applied to peasants who carried wine into Vienna.

Vienna is surrounded by a wall two thousand paces in circumference, but it has large suburbs with moats encompassing them, and a palisade all arouund. The city also has a...