Origins
The word 'govern' preserves what may be the oldest sustained political metaphor in Western civilization: the state is a ship, and the ruler is its helmsman. To govern is not to command or to conquer but to steer -- to hold the tiller and guide the vessel through uncertain waters. The metaphor encodes a specific vision of political authority: the governor's skill lies not in strength but in judgment, not in force but in navigation.
The word enters English around 1290 from Old French 'governer' (to govern, to steer, to direct), from Latin 'gubernāre' (to steer a ship, to direct, to guide, to govern), from Greek 'kubernân' (to steer, to pilot). The Greek word may derive from a pre-Greek Mediterranean substrate language -- a term borrowed from the seafaring peoples of the Aegean before the arrival of the Greeks. If so, the metaphor of governance as steering predates even the Greek civilization that made it famous.
The ship-of-state metaphor appears explicitly in some of the earliest Greek literature. Alcaeus (c. 600 BCE) used it in his political poetry. Plato developed it at length in the Republic, comparing the ideal ruler to a skilled navigator who guides the ship of state by knowledge of the stars (philosophy) rather than by the whims of the crew (popular opinion). The Latin adoption of 'gubernāre' for political governance carried the metaphor into Roman culture, and from there into every Romance language and into English.
Latin Roots
The derivative family in English includes 'government' (the act or system of governing), 'governor' (one who governs), 'governance' (the manner of governing), and the adjective 'gubernatorial' (pertaining to a governor), which preserves the Latin 'gubernātor' (helmsman, governor) more transparently than the French-derived forms.
The most surprising modern descendant of Greek 'kubernân' is 'cybernetics.' In 1948, the American mathematician Norbert Wiener published 'Cybernetics: Or Control and Communication in the Animal and the Machine,' coining the term from Greek 'kubernētēs' (helmsman, pilot, governor) to name the emerging science of control systems, feedback loops, and information flow. Wiener explicitly chose the word for its connection to governance and steering -- cybernetics was the science of how systems (mechanical, biological, social) steer themselves.
From Wiener's 'cybernetics,' the prefix 'cyber-' entered English in the late twentieth century, producing 'cyberspace' (coined by William Gibson in 1982), 'cybersecurity,' 'cybercrime,' 'cyberattack,' and dozens of other compounds. So the Greek helmsman's art of steering a ship through the Aegean has produced, by an unbroken etymological chain, the vocabulary of the digital age. 'Government' and 'cyberspace' are siblings -- both are about steering, separated by twenty-five centuries and the transition from wooden hulls to fiber-optic cables.
French Influence
The competing English word 'rule' (from Old French 'riule,' from Latin 'rēgula,' a straight stick, a ruler) encodes a different metaphor: to rule is to draw a straight line, to impose regularity. 'Govern' emphasizes responsive navigation through changing conditions; 'rule' emphasizes the imposition of straightness and order. The coexistence of both words in English gives the language two complementary models of political authority: the helmsman and the straightedge.