Ja'rod was the father of Duras, Lursa and B'Etor, and the leader of the Klingon House of Duras in the early 24th century. He was an old and bitter enemy of Mogh and the House of Mogh. In 2346, he moved to the colony on Khitomer. There, he transmitted the colony's defense codes to the Romulans, who used the codes to lower the colony's deflector shield and attack. In the ensuing massacre, over 4,000 Klingons were killed, including Ja'rod and Mogh.
Ja'rod's responsibility was unknown to the Klingons for the next twenty years, until a Romulan record of the attack on the outpost was discovered in 2366. However, by this time Ja'rod's son Duras had become politically powerful on the Klingon High Council, and the High Council chose to officially blame Mogh for the disaster instead, in order to keep the Empire from breaking into civil war. (TNG: "Sins of the Father")