Etruria was never a single cohesive state, instead being a collection of separate city-states that developed both alliances and conflicts with one other over time. Despite their cultural similarities, these cities produced artworks that reflected their own interests and whims, making it hard to always accurately identify Etruscan artworks. Another challenge stems from the Etruscans' failure to live in isolation from other Mediterranean cultures. Ideas and artifacts from Phoenicia, Greece, and the East arrived in Etruria via the ancient Mediterranean's well-established trading networks.