Lursa was a female Klingon officer of the 24th century Klingon Empire and member of the House of Duras. She was the elder of the two Duras sisters, herself and B'Etor, sister of Duras and daughter of Ja'rod. Through Duras, she had a nephew, Toral. She was the mastermind behind her family's fight to head the Klingon Empire.
Together with B'Etor, she was responsible for the beginning of the Klingon Civil War in 2367. With the assistance of the Romulans, Lursa and B'Etor plotted to install Toral, the illegitimate son of Duras, on the throne of the Klingon High Council. She attempted to persuade Jean-Luc Picard, who was the Arbiter of Succession, to rule in favor of Toral. When Picard supported Gowron, she and her sister took up arms against Gowron. Their attempt was defeated when the Federation blockaded delivery of supplies from the Romulans. When the Romulan involvement was exposed, Lursa's support evaporated. (TNG: "Redemption", "Redemption II")
The Duras sisters were also responsible for selling bilitrium to Bajoran Kohn-Ma terrorists in 2369. This plot was revealed through investigation by Elim Garak and Julian Bashir. They did this in order to obtain capital to rebuild their forces. (DS9: "Past Prologue") Another capital-raising scheme had them seizing a Pakled magnesite mine on Kalla III, overseen by the Dopterian Gorta, and selling its explosive ore to a Yridian, Yog. In 2370, they were also falsely accused of plotting to kill Worf and his son. During that same year, she was pregnant with her first child. (TNG: "Firstborn")
In 2371, the sisters worked with El-Aurian scientist Tolian Soran and raided a Romulan outpost to acquire trilithium in exchange for Soran's trilithium weapon. Lursa died above Veridian III when her Bird-of-Prey was destroyed by the USS Enterprise-D. (Star Trek Generations)
Lursa was played by Canadian actress Barbara March.
Walsh's costume from the episode "Past Prologue" was later worn by actress Peggy Jo Jacobs in the Star Trek: Voyager episode "Prophecy" and was sold off at the Christie's auction in New York.  Barbara March was interviewed by Ian Spelling for the Star Trek Generations - Official Movie Souvenir Magazine for the article "Barbara March & Gwynyth Walsh: Lursa and B'Etor", p. 72 in 1994 and for Star Trek: Communicator issue 104, pp. 51-52, article "The Klingon Way: Lursa".
In Star Trek Online, Lursa's child is a son, named Ja'rod after his grandfather. He was raised by the House of Torg following the deaths of his mother and aunt in battle with the Enterprise-D, and became head of the House of Duras upon reaching his Age of Ascension. Ja'rod rose to the rank of Captain in the Klingon Defense Forces, and took command of the IKS Kang after slaying his captain for not investigating the Undine infiltration in the 2390s.