Luke Duke was a character on The Dukes of Hazzard, more specifically he was one of the Duke Boys, who were argueably the stars of the show (I say argueably because Daisy Duke's shorts often ended up taking top billing). Luke was the most educated and oldest of the Duke cousins, although not by much. He is an ex-marine but obviously that had little bearing on the show, as he still showed the same "good old boy" mentality as everyone else. He was once engaged to a lady by the name of Candy Dix, who later became a singer (I never saw that episode, but several websites mention it).
Luke had quite a talent for music, just like his younger cousin Bo. In general, he was the more responsible of the 2 Duke boys, even though he didn't get to drive the General Lee nearly as much as Bo did. But when he did drive it, he was sure to get them out of trouble quickly. When talking on the radio Luke's CB handle was "Lost Sheep #1". That might not seem like important information, but CB radio played a big part on The Dukes of Hazzard.
Both of the Duke boys were accomplished automobile drivers. They decided to put that to good use when they spent some time on the NASCAR circuit in late 1982, and early 1983. Soon after which Luke found out that his long believed dead baby brother, Judd, was actually alive and well.
The Dukes of Hazzard had a lot of associated merchandise and toys back in the early 80s. Mego even released a "Luke Duke" action figure in 1981. He wore blue clothes, didn't actually look much like Luke, and was of a very shoddy design. But of course this "rare" figure is extremely collectable today. There were two different versions of it, it seems one version had an ugly head, while the other version had an even uglier head.
Luke Duke was played by Tom Wopat who later went on to have a career as country western music performer.