The demon Neron engaged Diana in battle and managed to kill her. The Olympian Gods granted Diana divinity and the role of the Goddess of Truth who started to reside in Olympus; her mother Hippolyta then assumed the role of Wonder Woman and wore her own different incarnation of the costume. In Wonder Woman Vol. 2 #136, Diana was banished from Olympus due to interfering in earthly matters (as Diana was unable to simply watch over people's misery on Earth). She immediately returned to her duties as Wonder Woman, but ran into conflicts with her mother over her true place and role as Hippolyta seemed accustomed to her life in America. Their fight remained unsolved, as Hippolyta died during an intergalactic war. Themyscira was destroyed during the war, but was restored and reformed as a collection of floating islands. Circe later resurrected Hippolyta in Wonder Woman Vol 3 #8.
The Lasso of Truth forces people to tell the truth. It was forged by Hephaestus from the Golden Girdle of Gaea that Antiope had once worn. It is able to restore people's lost memories get rid of illusions or cause illusions to those it holds and heal the holder's body cure insanity and protect people who are in close proximity to it from magical attacks. In the golden age version the lasso could also take on a rigid form and hold people aloft from a great distance away. During these eras, the lasso also forced those who were bound by it to act as the holder demanded. This trait also affected Wonder Woman. A non-combat application of the lasso is that it can be used to change Diana's clothes as long as those clothes are "in the right frequency" as the lasso. Although this was a plot device used more often in the golden and silver age in has been used on occasion in modern comics as for instance one time Diana transformed into a Miss America costume. The lasso is essentially indestructible, and can be offensively used in combat to incapacitate, and even attacking their souls.
Writer Gerry Conway brought Steve Trevor back to life again in issue #271 (September 1980). Following Diana's renunciation of her role as Wonder Woman, a version of Steve Trevor from an undisclosed portion of the Multiverse accidentally made the transition to Earth-One. With Diana's memory erased by the Mists of Nepenthe, the new Steve again crash-landed and arrived at Paradise Island. After reclaiming the title of Wonder Woman, Diana returned to Military Intelligence, working with Trevor and re-joined by supporting characters Etta Candy and General Darnell.
Due to the reboot of the character following Crisis on Infinite Earths, numerous things no longer made sense in terms of continuity as it related to the remainder of the DC Universe. As her first overall appearance was now in continuity around the Legends miniseries, it no longer made sense that she was a founding member of the Justice League of America. This founding position was instead given retroactively to Black Canary. Later it was decided that she should be given this position back and thus both she and Black Canary were considered founding members of the Justice League. In reference to the Justice League though, although she has more than 400 combined appearances therein, she has had most of her character development in her own series.