Worf, son of Mogh (
Worf’s family ties are slowly revealed across several hundred episodes and the movies. An important aspect to understanding Worf is that he was adopted by Federation parents, so he has both adoptive and biological family.
The House of Mogh was a family of high social and political rank which was for a time represented on the Klingon High Council. In Star Trek VI: The Undiscovered Country (set around 70 years before the Next Generation era began), Colonel Worf (also portrayed by Dorn) appears as the legal advocate of Captain James T. Kirk and Dr. Leonard McCoy after they are accused of killing Chancellor Gorkon of the Klingon High Council. He was also a member of the Klingon delegation at Camp Khitomer. Although not explicitly stated, he was intended to be Worf’s grandfather.
Worf has a son named Alexander with a half-human half-Klingon woman named K’Ehleyr, a character introduced in “The Emissary“, however she is later killed in “Reunion“, a “sequel” to that episode and part of the Worf story arc, leaving Worf as a single parent. Worf fathers a son with K’Ehleyr, Alexander later has to live aboard Enterprise-D when K’Ehleyr is killed. After TNG ends, Worf gets moved to the Deep Space Nine space station where he eventually marries the Trill symbiont Jadzia Dax. (see “You Are Cordially Invited…“) On DS9 Worf misses the Enterprise-D “family” that he had, often bemoaning the cut-rate work ethic and unfriendliness on the wayward outpost.
The episode “Sins of the Father” introduces Worf’s long lost brother Kurn, who is also an orphan of the House of Mogh. His adoptive parents have another son, Nikolai Rozhenko whom Worf grew up with. Nikolai and Worf interact in “Homeward” where it is revealed that Worf will likely have a nephew or niece.