Geometric art is a phase of Greek art, characterized largely by geometric motifs in vase painting, that flourished towards the end of the Greek Dark Ages and a little later, c. 900–700 BC. Its center was in Athens, and from there the style spread among the trading cities of the Aegean. The so-called Greek Dark Ages were considered to last from c. 1100 to 800 BC and include the phases from the Protogeometric period to the Middle Geometric I period, which Knodell calls Prehistoric Iron Age. The vases had various uses or purposes within Greek society, including, but not limited to, funerary vases and symposium vases.