The Trojan War was started, in the mythological account, by Paris, a prince of Troy, who awarded the golden apple to Aphrodite after she promised him Helen, the most beautiful woman alive. That judgment triggered a chain of oath-bound alliances and a Greek expedition. The war itself, in Homer's telling, lasted ten years — though most of that time was spent raiding and besieging, not in fixed battle.
The judgment that launched a thousand ships
The contest of the apple is the mechanism everything else hangs on, so it is worth tracing precisely. At the wedding of Peleus and Thetis, Eris — the goddess of strife, deliberately excluded — threw down a golden apple inscribed "to the fairest." Hera, Athena, and Aphrodite each claimed it. Zeus, unwilling to arbitrate, routed the decision to a mortal herdsman on Mount Ida: Paris, an unknown Trojan prince.
Each goddess offered a bribe. Hera promised dominion over Asia; Athena promised victory in war and wisdom; Aphrodite promised the most beautiful woman in the world. Paris chose Aphrodite. The most beautiful woman was Helen — already married to Menelaus, king of Sparta.
This matters because the choice converted a beauty contest into a political contract. Aphrodite's promise required Paris to take Helen from another king's household. The bribe, not the apple itself, created the grievance. When Paris carried Helen to Troy, Menelaus invoked the oath the suitors had sworn — to defend whoever Helen chose — and the coalition assembled.
Why the oath bound every Greek king
Helen had been courted by nearly every eligible Greek ruler. Her stepfather Tyndareus, fearing a war among the suitors, made them swear a pact: whoever won Helen, the others would defend his claim. The oath therefore functioned as a mutual-defense treaty binding dozens of kingdoms to one abduction.
The oath is the deeper "why." Without it, Menelaus would have sailed with Sparta's own levies and likely failed. With it, Agamemnon could summon the alliance that produced the largest expedition in Greek myth — traditionally 1,186 ships, per the Catalogue of Ships in Iliad Book 2, carrying contingents from across the Aegean. The figure is poetic, not a census.
Plainly: the apple started the argument, and the oath turned it into a coalition war.
Timeline of the conflict
| Phase | Traditional duration | Key event |
|---|---|---|
| Judgment of Paris | Before the war | Golden apple awarded to Aphrodite |
| Helen's abduction | Immediate | Paris takes Helen to Troy |
| Coalition muster | Months | Oath-bound kings assemble at Aulis |
| Sailing and first landing | Days | Greeks reach the Troad; first skirmishes |
| Siege of Troy | ~10 years | Raiding, attrition, intermittent battles |
| Plague and quarrel | Year 10 | Apollo's plague; Agamemnon takes Briseis |
| Wrath of Achilles | Weeks | Achilles withdraws; Patroclus killed |
| Fall of Troy | Final days | Wooden horse; city sacked |
The ten-year figure is the standard answer, but the Iliad covers only about 51 days in the war's tenth year. Most of the "ten years" is narrative backdrop, not depicted combat.
Ten years that were mostly not battle
The Iliad's compressed timeframe is the most counterintuitive detail in the whole cycle. Homer begins in year ten and ends before the city falls. The poem covers roughly seven weeks of action — the quarrel, the fighting, Patroclus's death, and Hector's death. The sack of Troy sits outside the Iliad entirely, told in later epics.
What filled the other nine years? Raiding the surrounding coast, securing supply lines, and camping on the beach at the Troad. The Greeks could not breach Troy's walls, and the Trojans could not dislodge the Greeks from their fortified camp. It was a stalemate of attrition, not a decade of pitched battles.
This is where professional caveats enter. "Ten years" is a traditional literary figure, not a documented campaign. Historians debate whether a historical Trojan War occurred at all, and if so, whether it was one war or several layered conflicts. The archaeological destruction layers at Hisarlik (the site of Troy) show multiple Bronze Age destructions, which complicates any single-war claim.
Misconceptions that survive despite the sources
The most common errors are worth naming directly, because they distort the "who started it" answer.
The apple was addressed to "the fairest" but the choice belonged to a mortal, not Zeus — Zeus ducked the decision on purpose. Paris did not "steal" a willing Helen in every version; some sources insist she was abducted, others that she went willingly, and the Iliad barely adjudicates it. The Trojan Horse appears in the Iliad only obliquely and in later tradition — it is not the poem's climax. Helen's face "launching a thousand ships" is a later idiom, not Homeric phrasing. The war did not begin over a single insult; it began over an oath network and dynastic politics.
Red-flag warnings for careful reading:
Do not treat the Catalogue of Ships ship counts as historical records. Do not assume "ten years" reflects a measured campaign. Do not collapse the Iliad's timeline with the whole war cycle. Do not treat myth as testimony without naming the source tradition.
Comparison: the three goddesses and their offers
| Goddess | Offer to Paris | Consequence |
|---|---|---|
| Hera | Dominion over Asia | Political power, rejected |
| Athena | Victory and wisdom in war | Military prowess, rejected |
| Aphrodite | The most beautiful woman | Helen, chosen |
| (Eris) | Strife and discord | Set the contest in motion |
| (Themis/Tyndareus) | The suitors' oath | Converted choice into coalition |
The table shows the structural logic: each offer maps to a domain — politics, war, love — and Paris's selection routes the conflict into the domestic sphere, which is precisely why a coalition of kings had to enforce it.
What actually started it, in sequence
Reduce the myth to causal steps and the "who started it" answer sharpens. Eris started the contest. Paris started the grievance by accepting Aphrodite's bribe. Aphrodite started the abduction by delivering Helen. Helen's abduction activated the oath. The oath started the coalition. Agamemnon's command started the expedition. So "who started it" depends on which layer you are asking about.
This layered causality is why thin explainers oversimplify. The apple is the trigger, the judgment is the decision, and the oath is the mechanism that made the decision catastrophic.
Practical actions for reading the sources
If you want to engage the question responsibly, treat it as a source-critical exercise rather than a trivia lookup.
Read the Iliad's Book 2 catalogue for scale, but label its numbers as epic convention. Compare the Iliad with the later Trojan cycle epics for events beyond the poem. Check archaeological summaries of Hisarlik before asserting a historical war. Distinguish "who caused the mythic war" from "whether a war occurred." Note that Homer does not narrate the judgment of Paris directly; it is referenced, not staged.
Plainly: decide which question you are answering — mythic cause or historical event — before defending an answer.
Limits of the evidence
The limits are sharp and worth stating plainly. The Trojan War as told is a literary construction, not a documentary record. There is no contemporaneous Bronze Age archive naming Paris, Helen, or a ten-year siege. The Iliad was composed centuries after any plausible historical conflict and shaped by oral tradition. The "ten years" and the 1,186 ships are traditional figures, not measurements.
Whether a historical war underlies the legend remains contested. Excavations at Hisarlik reveal a fortified settlement with destruction layers, but attributing any layer to a specific Greek campaign exceeds the evidence. The honest answer separates the mythological cause — the apple, the judgment, the oath — from the historical question, which the current evidence cannot settle.