The Gathering of the Gods was a meeting between human druids and priests, elves, and dryads in the Year of the Dawn Rose, 720 DR, when several deities of the Faerûnian pantheon spoke to one another, along with the attendees, by temporarily passing into the bodies of their faithful servants. This congregation of elves and humans, blessed by deities from both of their pantheons, led to the founding of the Harpers, the semi-secret society that fought against tyranny and subjugation in all forms.
During the 8th century DR, waves of human settlers from the Vilhon Reach, specifically those who worshiped the malevolent gods Bane, Bhaal, Myrkul, Malar, and Loviatar, set out on a campaign of conquest to the north. While their lands were sufficiently abundant and served their people well, they grew bored and restless and set their sights on the lands of Dragonreach. Their violent settlers infringed upon the fair folk of Elventree, along with those in the surrounding Cormanthyrean settlement of Tangled Trees.
In an act of unprecedented cooperation, the elves reached out to nearby human clergies and sought a meeting to be held in secret. It would take place a few days before Midsummer, on Flamerule 27, 720 DR, at the Dancing Place in High Dale.
Shortly after dusk, after a score of dryads had appeared with their blessing, the various groups settled into the meeting place. The native druids of Silvanus were shortly joined by all manner of folks, from weary travelers to riders who entered atop winged beasts to magic users who arrived via teleportation. In all, clergies from the faiths of Deneir, Eldath, Lliira, Mielikki, Milil, Mystra, Oghma, Selûne, and Tymora and elven servants of the Seldarine were all in attendance.
The hot-tempered wizard Elminster spoke first, addressing the elves' concern with a call-to-action. They sought a sort of "shadowy band of heroes" that would take action against any power that grew too large and disrespectful, fight against the forces of tyranny and oppression, serving no god but the collective many groups that had no army of their own.
The priests began their debates with cold and dispassionate manners, having little to no experience working with peoples of other faiths. They gave little in the way of compromise or cooperation, afraid that capitulation would see their god given less importance than another. As the meeting progressed, arguments became impassioned and even fiery, until it was apparent to all that some of the bodies of these divine servants were occupied by the gods themselves. Those mortals left at the gathering were left speechless, staring in awe as the deities of elves and men openly discussed the matters of the world on Faerûn.
In the end, the gathered gods decided to support the formation of an organization that worked for the many but served none. These Harpers would be granted supernatural powers, one from each deity in attendance, to aid them in their mission.
It was this supernatural occurrence that imbued the Dancing Place with restorative properties. Any ill creature that slept overnight upon the forested hill found itself healed. Conversely, some of the priests' bodies that played host to their deity aged many years in a single night, twisted by the sheer knowledge of their patron's beliefs and divine opinion.