The Taken King launched on September 15th, with the newest raid going live on September 18th. The raid is the largest to be released for Destiny.
And it was beaten hours after its launch. The 6 man fire team was neck and neck with 2 others, but in the end it was Gunny629, TheTeawrex, Rebelize_ Charionna, Professorbroman, and Gothalion as the first fireteam to take down Oryx.
Bungie also tweeted out to commend Versusthestream, who was presumably the second team to take down the Fallen King.
Congratulations to https://t.co/zFbntR4sg1 who just killed Oryx. The king has fallen again.
— Bungie (@Bungie) September 19, 2015
The image below, originally uploaded by Gamespot, has the stats for the first successful run in the raid. Have you adventured into the raid and taken down Oryx yet with your fireteam?