Alexander Rozhenko

Alexander Rozhenko was the son of Worf and Federation Ambassador K'Ehleyr. He was conceived in 2365 and born on the forty-third day of Maktag in 2366.

Alternate timeline
In an alternate timeline, in the 25th century, Alexander was Klingon Ambassador to the Federation. He commanded the IKS Ya'Vang and met with the USS Excelsior to share and witness the first stages of time-travel technology by the Federation. (: "Temporal Doom! Part II")

He had grown apart from his father, Worf, due to his own responsibilities taking up most of his time. This would eventually lead him to later lose his father the way he had lost his mother. He then found alien passage through time, and travelled back to 2370 where we would attempt to warn Worf on the Enterprise of future events. ( "Firstborn")