Although there is no written record of exactly how the idea came up it is probably safe to say that 'neccessity is the mother of invention'. When people need a way, they will usually find it.
Odysseus got the idea.
The Trojan horse was Odyseus' idea (Ulysses) but the goddess of wisdom, Athena gave him the idea.
Odysseus
the new that menelus gives is that it was odyessu's idea of the horse
Odysseus came up with the giant wooden horse idea to trick the Trojans and conquer Troy.
The horse is said to have been the idea of Odysseus.
The idea of the wooden horse during the Trojan War is attributed to the Greek hero Odysseus. According to legend, he devised the cunning plan to build a massive wooden horse, hide soldiers inside it, and present it as a gift to the Trojans. The ruse successfully led to the fall of Troy when the Trojans brought the horse into the city, allowing the Greek soldiers to emerge at night and open the gates for their comrades. This story is famously recounted in Virgil's "Aeneid" and other classical texts.
The idea to create the wooden horse that ultimately led to the destruction of Troy is attributed to the Greek hero Odysseus. He devised the cunning plan as a deceptive gift to the Trojans, suggesting it was a symbol of their victory and a means to end the long siege. This strategy allowed the Greeks to hide soldiers inside the horse, enabling them to infiltrate the city once the Trojans brought it inside their walls.
Was it a real horse ? Not when made from wood. Was a wooden horse really built and filled with soldiers ? Until recently the general opinion was a resounding yes. Now the answer would be yes, probably, but some archeologists are having doubts.
Troy "died" from being defeated by another army. this was done with the help of the Trojan horse. which was a big wooden horse that solders hid inside and defeated troy. (the Trojan horse was crated by Greek warriors and Odysseus came up with the idea.)
The gods split into two sides Greeks and Trojans. Athena was on the Greek side and came up with a plan to hide some Greek soldiers into a wooden horse. they gave the horse to the Trojans and the Greek soldiers inside waited until all the Trojan soldiers fell asleep and attacked. then the Greeks won because of Athena's smart plan.Odysseus also was with the Trojan horse because Athena helped him come up with the idea so they both get credit on the idea.
Odysseus thinks up the Trojan horse. A large scale wooden horse... which is hollow. Greek troops hide inside and one person is left outside the horse to explain that the horse is a gift from he surrendering Greek troops (inside the horse). Trojans wheel it into their city and at night when they are all asleep the Greeks take over the city.