Notes : The product of a Human father and Klingon mother, B'Elanna Torres had a difficult childhood. She lived on Kessik IV, a Federation colony at which she and her mother were the only Klingons. Her father abandoned the family when she was five, and her mother moved to the Klingon homeworld. B'Elanna joined Starfleet academy when she was 18, but her time there was turbulent; she argued constantly with many of her tutors, constantly challenging their methods and assumptions. After her second year she left the academy, unaware that at least one of her tutors was so impressed with her ability to question him that he left a letter in her permanent file saying that he would fully support her if she wished to rejoin.

B'Elanna subsequently joined the Maquis, and spent some months fighting the Cardassians. In 2371 she was part of the crew of the vessel dragged to the Delta Quadrant by the Caretaker, and after the loss of her ship she was forced to become a member of the USS Voyager's crew. B'Elanna continued to have difficulty fitting in with Starfleet, and assaulted at least one member of the engineering crew. Despite this, Captain Janeway appointed her as Chief Engineering Officer. B'Elanna eventually adapted to Starfleet methods and came to excel in her new role.

She continued to have difficulty accepting her Klingon nature, but gained a different perspective on this when a Vidiian scientist used that species advanced medical technology to split B'Elanna into two separate people, one Klingon and one Human. She subsequently made more of an effort to accept her Klingon half, and at the prompting of Tom Paris began to recreate and participate in some Klingon rituals.

In 2374 B'Elanna and Tom became romantically involved, and despite some difficult tensions this relationship continues to the present.