When DeForest Kelley passed away on June 11, 1999, Star Trek fans mourned the loss of not only one of the Original Series' most beloved characters, but a man of good grace and character. Kelley was instrumental in defining the very essence of Star Trek. Whereas William Shatner's Kirk was the brash, bold heart and Leonard Nimoy's Spock was the unemotional, logical brain of the show, Dr. Leonard H. McCoy was the soul, much of that thanks to Kelley's portrayal.

In every Star Trek series, a doctor is necessary — dramas often revolve around whether or not a crucial character can be saved, or a cure to a strange disease can be found. But what Kelley brought to Star Trek transcended serving the mere function of ship's physician; he would weigh in on Captain Kirk's decisions, whether his opinion was asked for or not, and brought his own folksy-yet-wise humanity to the table every time. His ongoing gentle jousting with Spock not only provided comic relief, but helped to underscore the show's themes of humanity retaining its moral and ethical center in the far future.

Like his U.S.S. Enterprise counterpart, Jackson DeForest Kelley hailed from the South, having been born in Atlanta in 1920. The child of a Baptist minister, he sang in the church choir, which eventually led to radio performances and, ultimately, to a cross-country move to California. There, Kelley worked in live theatre and radio and, after making a Navy training film during World War II, he began working in film and later television, often playing villains and working regularly in Westerns. When Star Trek finally hit the airwaves in 1966, his colleague Gene Roddenberry, who had worked with Kelley previously on several pilots, cast him as Dr. McCoy.

After Star Trek, Kelley enjoyed a semi-retirement with his wife Carolyn, working primarily when the good doctor's presence was required, such as the Animated Series in the early '70s or the first six Star Trek motion pictures. When Star Trek: The Next Generation debuted in 1987, Kelley delivered a cameo in "Encounter at Farpoint" as the beloved Dr. McCoy, now a retired Admiral in Starfleet. His final performance as Dr. McCoy took place alongside his TOS castmates in the 1994 computer game "Star Trek: Judgment Rites."

Biographers Terry Lee Rioux ("From Sawdust to Stardust") and Kristine M. Smith ("DeForest Kelley: A Harvest of Memories") have authored extensive profiles of the man who was too humble to write about himself.

"De was just a decent guy who led a quiet-but-impressive life wherever he went," says Kris Smith in an interview here on STARTREK.COM. "Every life he touched was blessed in some way, from the checker at the market to the heads of studios. He walked the walk, in love." (Smith is writing another book, "The Enduring Legacy of DeForest Kelley: Actor, Healer, Friend," and is looking for stories from fans, friends and coworkers who knew him. She can be reached at kristinemsmith@msn.com.)

At various conventions, Rioux has told fans, "One of the things I want you to understand, if nothing else, is how much he loved you."

Let us celebrate DeForest Kelley's life on his birthday, and take a moment to reflect on all of the wonderful and thoughtful moments he gave Star Trek and to the world.

Post your own birthday tribute message on the Star Trek Message Boards!