Final answer:
The ancient Greek city-states were tied together by a common language, religion, and culture, as well as by Panhellenic sanctuaries and festivals like the Olympics. Political alliances and collective opposition to threats, such as the Persians, also united them. Despite political diversity, the shared Hellenic identity fostered a vast Greek civilization.
Step-by-step explanation:
The independent city-states of Ancient Greece, known as poleis, were held together by shared language, religion, and culture. Besides these cultural ties, the ancient Greeks participated in Panhellenic sanctuaries and festivals like the Olympics, which fostered a sense of unity and common identity despite political fragmentation. This alliance was often reinforced in the face of external threats, exemplified by the collective defense against the Persian invasions.
The Panhellenic tradition, particularly visible during the Olympic Games held at the sanctuary at Olympia, became a key fixture in promoting unity among the varying city-states. Additionally, Greek life was deeply influenced by its political systems and the consistent emphasis on a shared Hellenic identity, as they often united against common enemies like the Persians, and later, the conquests that would bring them under Macedonia's control.
It is pivotal to note that the Greek civilization was expansive and not confined to a single geographic location or governance structure. Colonies and poleis spread across the Mediterranean contributed to a common Greek cultural identity that resonated throughout the region, both during and beyond the timeframe of these independent city-states.