Many things change over time. Europe is not different in this aspect. Europe goes through a roller coaster ride of ups and downs throughout the time period between 100 BCE and 1500 CE. In the beginning, ideas and basic principles are formed mostly in the cities, like Rome. In the middle time period, Europe goes through a dark period where warfare is everywhere and people were living in chaos. At the end of this time period, urbanization has Europe in a prosperous state with help of revolutionizing the ideas from the Middle East.
In the period between 100 B.C.E. to 350 C.E., it was part of the age of the Roman Empire in Europe. Roman society was one of the first empires to be run controlled through cities. Rome was an urban empire and it was ran by the city-states, which had an urban center and the surrounding agricultural territory. Governments were located in the cities so people living in rural area had little contact or no contact with them. Rome was a monarchy with a king having control over everything. The Roman state prospered for two-and-a-half-centuries after Augustus stabilized the internal political situation and addressed the needs of the empire with an ambitious program of reforms. The cities as well as the rural areas were starting get well off. However, in the 3rd century C.E., political, military, and economic problems beset and nearly destroyed the Roman Empire, at the same time, the neighboring Germanic raiders attacked the borders of Rome. This in turn led to urban chaos and cities were destroyed.
From around 300-1200 B.C.E., Europe entered the age of darkness and feudalism. The Roman empire was split in two. The Byzantine Empire in the East that split off Rome continued order and urban life while the rest of Europe was thrown into chaos. The disappearance of the legal framework of unity and order that had persisted throughout the Roman Empire and the fragmentation of allegiance among kings, nobles, and chieftains brought dramatic changes in the political landscape.