Word
Hegemon
A state powerful enough to dominate its region or era and set the rules the other states follow
Examples
Sparta entered the war as the acknowledged hegemon of the Peloponnese, the large southern peninsula of Greece, and the rise of Athens threatened that standing.
Analysts still argue whether a rising power can overtake a reigning hegemon without a war.
Origin
From Greek hēgemōn, “leader” or “guide,” from hēgeisthai, “to lead.” Greek writers used hegemonia for leadership of an alliance of city-states: Sparta held it over the Peloponnesian League, while Athens turned a naval league into an empire under its own leadership.
How it connects
This is the name for the ruling power whose position the riser threatens.
This word appeared in When a rising power meets a ruling one, the Involves connection for August 18, 2026, which asked: Why do a rising power and a ruling power so often end up at war?
Check yourself
Which situation best describes a hegemon?
A state that dominates its region and sets the rules the others follow.. Right. Hegemony is dominance over states that remain formally independent: the hegemon sets the rules without governing directly.
What the sources establish
Hegemon derives from the Greek hēgemōn, “leader,” and Greek usage applied hegemonia to leadership of alliances of city-states.
Hegemony describes dominance over formally independent states, which distinguishes it from direct imperial rule.
Sources
History of the Peloponnesian War (Thucydides, 1874), Book I, chapter 23 (the truest cause); Book V, chapter 26 (the author's exile)
hegemony (Online Etymology Dictionary), Entry for “hegemony”: Greek hēgemōn, hēgeisthai