Once upon a time, there was an ancient city on the coast of Turkey named Troy.
The city of Troy was protected by a high wall built around the city. Some parts of the wall were 20 feet high!
At the time of this story, Greek warriors had been trying to breach the wall around Troy for about ten years. The Greeks could not find a way in, and the Trojans did not seem able to drive the Greeks away.
Odysseus suggested the Greeks build a huge, heavy, beautiful wooden horse, and leave it outside the gates of Troy. Then, the entire Greek army would pretend to leave, as if they were headed for home. But it was a trick.