However, once the Legion's campaign ended, Caesar broke the alliance and betrayed the tribe.
They forged an alliance with the fledgling Caesar's Legion in 2247. New Vegas' Ulysses was once a member of the Twisted Hairs, a powerful tribe in Arizona. While Ulysses' true identity is unknown, he chose his name in honor of the General and President Ulysses S. In every major DLC afterwards, he's mentioned until finally, during the events of Lonesome Road, he reveals himself as Ulysses.
In the base game, this person is first referenced by Johnson Nash in Primm, who explains that they were originally meant to carry the package that nearly got the Courier killed. Throughout the Courier's travels through the Mojave in Fallout: New Vegas, players can't help but notice that there's someone who knows who they are shadowing their every move.