http://en.wikipedia.org/wiki/Justice_League_Unlimited#Connection_with_Batman_Beyond The term "Justice League Unlimited" was used first in the two-part episode ("The Call") of the animated series Batman Beyond that aired more than a year before the first Justice League series began. Decades into the future of the DC Animated Universe, the Justice League still exists, and is referred to as the "Justice League Unlimited". This future League consists of Superman, a new Green Lantern, Big Barda, Warhawk, Aquagirl, and Micron. Like his predecessor, the new Batman becomes a part-time member of the League. Justice League Unlimited's first season two-part finale ("The Once and Future Thing") again features the league of the future, with a reduced lineup. Villain David Clinton and the Jokerz killed most of the future members of the league, leaving only the original Batman (now the 80-year-old Bruce Wayne), the second Batman (Terry McGinnis), Warhawk and Static alive. This episode also features the revelation that Warhawk is the son of John Stewart and Shayera Hol. Some of these members appear again, along with the rest of the now-restored future heroes, in the season two finale, "Epilogue".