city state · Greece and the Aegean
Keos
Origins
Keos lies off the tip of Attica and had a major Bronze Age town at Ayia Irini. In the early Iron Age Ionian Greeks settled it, and the island was organised as a tetrapolis of four cities, Ioulis, Karthaia, Koressia and Poiessa, which sometimes acted together as one state.
Rule and society
Keos was famous for its poets: Simonides and his nephew Bacchylides, both from Ioulis, wrote for patrons across Greece in the 6th and 5th centuries BCE. Strabo records a Keian law said to require citizens over sixty to drink hemlock. The island exported ruddle, a red earth pigment, and paid tribute in the Delian League.
Decline and legacy
Keos joined the Second Athenian League but revolted in the 360s BCE and was subdued. In the 3rd century BCE Koressia became a Ptolemaic naval base renamed Arsinoe. The island passed under Roman control by 146 BCE.
On the connections map
Open the full map →Connections (2)
- Keos was part of Delian League478 BCE – 404 BCE
- Keos was part of Nesiotic League314 BCE – 167 BCE
More states of Greece and the Aegean →
Cite this page
- APA
- The Epoch Institute. (2026). Keos. In The Epoch Institute States Register. https://the-epoch-institute.org/state/keos
- MLA
- “Keos.” The Epoch Institute States Register, The Epoch Institute, 2026, https://the-epoch-institute.org/state/keos. Accessed .
- Chicago
- The Epoch Institute. “Keos.” The Epoch Institute States Register. 2026. https://the-epoch-institute.org/state/keos.
- Harvard
- The Epoch Institute (2026) ‘Keos’, The Epoch Institute States Register. Available at: https://the-epoch-institute.org/state/keos (Accessed: ).
Last reviewed October 2026Random state ↻