Taken on its own, the story of the Judgement of Paris is actually a fairly simple one — a story that seems almost comedic, in nature. Yet, it is also a small part of a much larger story — one that begins with what should have been a simple contest, but which ends with the destruction of the city of Troy.
The wedding of the sea nymph, Thetis, to the mortal king, Peleus, was set to be a lavish affair. Along with the greatest kings of Ancient Greece, it was a wedding to be attended by all of the gods of Mount Olympus — all, except for one. Fearing that she would inevitably cause some manner of disruption Eris, the Goddess of Strife and Discord, was not invited to attend. When Eris put in an appearance anyway, she was quickly turned away.
Eris was, quite naturally, angered by this insult. In the end, the issue of whether the Goddess of Discord actually would have ruined the wedding, had she been invited, became entirely moot. She was certainly willing to do so after being insulted so blatantly.
Eris was clever, though — simply disrupting the wedding, herself, was not good enough for her. Instead, the revenge that she planned was both subtle, and very simple. Travelling to the Garden of the Hesperides, an orchard belonging to the goddess Hera, where golden apples capable of granting immortality grew, Eris plucked the largest she could find from the branches of the tallest tree. On this apple, Eris inscribed the single word 'Kallistai', which roughly translates to 'to the fairest'. Making her way back to the wedding ceremony, Eris tossed the apple into the gathered throng of deities. Then, she fell back into the shadows to enjoy the result of her efforts.
Eris did not have to wait for long, of course. Upon seeing the apple, three goddesses immediately reached forward to claim it — each convinced that it was obviously meant for them. They were Hera, the wife of Zeus and Queen of Mount Olympus, Athena, the goddess of wisdom, and Aphrodite, the goddess of love.
With each believing that the golden apple was clearly theirs, the inevitable argument that ensued between the three goddesses brought on abrupt halt to what had been a joyous wedding ceremony — just as Eris had intended. Barely able to contain her own amusement, Eris slipped away before she was noticed. The three goddesses, meanwhile, turned to Zeus, demanding that the king of Mount Olympus should decide who was most deserving of the golden apple. Knowing that any decision he could make would earn him the anger of two powerful goddesses, though, Zeus wanted no part in this decision. Instead, the ruler of Mount Olympus immediately sought to pass the responsibility off onto someone else, by suggesting that a fair and impartial judge should be chosen.
Zeus's chosen judge was a young man called Paris — a shepherd who had already earned himself a reputation for fairness. Previously, Paris had come to the attention of the gods of Mount Olympus when, upon declaring one of his own bulls to be the finest in all of the world, he had found himself presented with a new bull that was actually the god of war, Ares, in disguise. For Ares, this had simply been intended as a joke — yet, he was still impressed when the young shepherd immediately recanted on his earlier boasting and declared that the disguised deity made for a much finer specimen than his own.
It was for this reason that Zeus came to the conclusion that Paris would be the most capable of making a fair and impartial decision between the three goddesses — and, Hera, Athena, and Aphrodite agreed with this decision. So, guided by the messenger god, Hermes, the three goddesses made their way to Mount Idea, where they confronted Paris and demanded that he make his judgement.
Despite his best efforts, though, Paris soon found that he could not choose between them. Each was beautiful, of course — but, their beauty was of such a different sort, that it proved impossible for Paris to fairly measure one against the other.
In time, the three goddesses began to grow weary of waiting for Paris to make his final judgement. So, each approached him in secret, attempting to sway his decision in their favour. Hera offered to make Paris the king of all of Europe and Asia, if he would declare her to the fairest of the three. Athena offered to grant him wisdom, and the skills of the mightiest warriors of ancient Greece. Aphrodite, meanwhile, offered him the love of the most beautiful mortal woman in all of the ancient world — Helen of Sparta, the wife of King Menelaus.
In the end, it was Aphrodite's promise that swayed Paris, and he presented the golden apple to her. This decision instantly earned him the enmity of both Hera and Athena.
Of course, Paris had never been a simple shepherd. In truth, Paris was a prince of the city of Troy — the son of King Priam. Upon his birth, it was prophesied that Paris would bring about the ruin of that grand city — and so, it was decided that he should be sent away.
In the years that followed, though, Paris was ultimately welcomed back to the city of his birth, and invited to claim his true status as prince. As he made his return to the city of Troy, though, Paris did so in the company of Helen who, with the aid of Aphrodite, he had managed to steal away from her husband.
When Paris returned to Troy, he brought the anger of a well-respected king and two powerful goddesses with him — setting in motion a series of events which would eventually lead to the Trojan War.