If actor, writer and comedian Larry David had only one credit to his name – that of co-creator of “Seinfeld” (NBC, 1989-1998); arguably the most popular and critically acclaimed situation comedy in the history of television, outside of possibly “I Love Lucy” (CBS, 1951-57) – his legacy would be well assured. Thankfully for audiences who knew him only as a name in the “Seinfeld” credits, the reluctant performer nevertheless segued into a surprising starring role as a more curmudgeonly version of himself on the hit improvisational HBO comedy series “Curb Your Enthusiasm” (2000- ) – a show which in tone and subject matter – as well as even occasional guest stars – reminded many of David’s first big hit in “Seinfeld” – a show “about nothing” that continued to delight longtime fans year after year in syndication.

Born Lawrence Gene David on July 2, 1947 in Brooklyn, NY, David was the younger of two sons born to his parents, a clothes salesman and a housewife. David described his childhood as “wonderful,” and drew much inspiration for his future comedy endeavors from his immediate surroundings – what with his aunt and cousins living in the apartment next door to his parents, and neighbors and relatives frequently entering and leaving the David’s home unbidden. At age 13, he met friend and future “Enthusiasm” co-star Richard Lewis – who was born just three days apart from David – at a summer camp in Cornwall-on-Hudson in upstate New York. According to both men, the pair took an instant dislike to one another that was not resolved until they met again over a decade later as stand-up comics in Manhattan.

David graduated from the University of Maryland at College Park with a degree in history and business, and then spent much of the 1970s trying to figure out a career path. He worked as an undergarment salesman, paralegal, cab driver, and limousine driver between bouts of unemployment. Eventually, like “Seinfeld’s” George Costanza (Jason Alexander) – the whiney loser always down-on-his-luck with work and relationships who was based on David’s own personality – returned to his parents’ home, where he was harangued about his unsure future. In the meantime, David cultivated an active dislike for mainstream culture; he found the fashion and attitudes of the 1960s and ‘70s counterculture too conformist, and shirked from popular trends – further material for his future comedic endeavors.

David began taking acting classes in Manhattan in the early 1970s and found humorous improvisation to be a comfortable fit for his sensibilities. Performing stand-up comedy seemed like a possible career for David, but his initial entry into that world proved a lot harder than anticipated. Comedy in the ‘70s was, for the most part, very mainstream and geared towards television appearances, and David – who often strode onstage in an Army jacket, wore glasses and was balding in his mid-30s; who built his stage act around seemingly nonsensical rants about oddities in language and human behavior – simply did not fit into that frame. That David would frequently harangue audience members for speaking during his act, or simply walk off stage if he felt their attention was not fixated on him, did not help his case as a testy oddball. But he was about to meet a comedic soulmate who not only “got him” but also managed to soften David’s rough edges with a more pleasant, accessible personality.

In 1976, David met an up-and-coming comic named Jerry Seinfeld, and the similarities between their material and world view helped to cement a tight friendship. Initially, David was the more successful of the duo – he landed a writing and performing job on the sketch comedy series “Fridays” (ABC, 1980-82) where he met future “Seinfeld” collaborators Larry Charles, Michael Richards, Melanie Chartoff and Bruce Mahler, and as a writer on “Saturday Night Live (NBC, 1975- ) from 1984-85, where he met Julia-Louis Dreyfus. The latter show proved particularly frustrating for David, who only landed one sketch on the show during his entire tenure before departing midway through the season. Legend had it that one night he quit “SNL,” but after walking out of 30 Rock and considering his financial situation, reportedly returned to work the next day after quitting and acting as if he had never left. This same plotline would face George Costanza, who in the midst of a hissy fit, walked out of a job, only to think better of it later and return the next day, pretending nothing happened.

Meanwhile, Seinfeld was quickly working his way up the comedy ranks with appearances on primetime talk shows and regular national club tours. In 1988, NBC approached him to develop a sitcom based on his material. Seinfeld immediately called on David to collaborate on the project, with the pair hitting upon an idea to pitch “a show about nothing” (which later served as the basis for one of the series’ most enduring episodes) in which two comedians would wander around New York commenting on everything they saw. The approach was immediately nixed by NBC in favor of a traditional three-camera style – but David and Seinfeld wanted the series to be shot with a single camera like a documentary, so they indulged the duo with a pilot.

David became the series’ show runner – its head writer and supervisor of the show’s tone and continuity – and found the same degree of resistance to his job there as he did during his stand-up days. He clashed openly with Seinfeld’s managers over the depiction of their client, and found the staff writers unable to reconcile with his vision for the characters – which was more self-obsessed, eccentric, and occasionally venal than most television characters at the time. He was also deeply opposed to episodes that were built around moral lessons or that ended happily. But the first season success of “Seinfeld” allowed David to mold a production team that was more in tune with his vision – with Charles being brought on board as supervising producer – and the program coalesced into the singularly unique version that caught fire with audiences in the early 1990s and never let up from that time on. For his efforts, Charles and his writing staff won two Golden Globe Awards and an Emmy, as well as numerous nominations.

David’s contributions to the series went beyond overseeing the writing of show. He penned some of its most enduring episodes, including “The Puffy Shirt” (Jerry’s girlfriend designs a horrible shirt which he wears on “Today”); “The Parking Garage” (the four get lost in a parking structure”); and “The Chinese Restaurant” (Jerry, George and Elaine resort to ridiculous measures to get a table at a Chinese restaurant). Many of the show’s most memorable episodes sprung from David’s own life. The character of Kramer (Michael Richards) was inspired by David’s own offbeat neighbor in New York’s Hell’s Kitchen, Kenny Kramer, and the infamous “Contest” episode, in which the four main characters attempt to refrain from masturbating, was based on a real-life competition he conducted with friends. David also staked out the office of a woman whom he had met but forgotten her name, and did actually steal the tape from the answering machine of a girlfriend so she would not hear his message (“The Phone Message”). David also played numerous small parts on the series; he was the voice of Newman prior to Wayne Knight’s casting (in “The Revenge,” Knight re-dubbed the lines for the syndicated broadcast); played the Greenpeace worker who floated out to sea with the president of NBC (Bob Balaban) in “The Pilot;” and lent his voice (and the back of his head) to a caricature of New York Yankees owner George Steinbrenner.

David left “Seinfeld” in 1996 on amicable terms, with him confessing during that period, that he felt he had contributed as much quality material as he could to the series, and wanted to leave on a positive note. Post-Seinfeld”, he spent the next year writing and directing a theatrical feature called “Sour Grapes” (1998), which failed both critically and financially. He returned to “Seinfeld” as executive producer for its final two seasons; his absence from the writing pen – save for the memorably strange series finale, which found all four characters incarcerated – was noted by critics and some of the staff (according to director Andy Ackerman, “Seinfeld” got “sillier” in David’s absence), though it seemed to have little effect on ratings. When the show came to a close in 1998, both David and Seinfeld found themselves in a staggering windfall of income thanks to syndication and DVD rights; by some accounts, David had earned over $500 million from his work on “Seinfeld.”

Now financially secure but without a project, David began mulling over a return to stand-up. He was approached by a writing acquaintance, actor Jeff Garlin, who offered to direct a comedy special for David for broadcast on HBO. The pair then devised an idea to turn the traditional comedy special into a “mockumentary” about David’s return to stand-up, with David as his cranky self, Garlin as his manager, and Groundlings performer Cheryl Hines as David’s wife (in real life, David was married to former talent coordinator-turned-environmental activist Laurie Lennard; the couple would separate in 2007). The key element to the special, titled “Larry David: Curb Your Enthusiasm,” which aired on HBO in 1999, was that the entire show would be improvised by its cast, which would operate from detailed synopses written by David. The show, which was filled with David’s friends and cohorts – including Jason Alexander, Seinfeld, Richard Lewis, and other comics – was filmed in a documentary style by real-life documentarian Robert Weide, and focused less on David’s actual stand-up performance than on his character – a hyper-realized take on David’s own eccentricities – and the havoc those eccentricities wreak upon him and those around him.

The show received mostly positive reviews, but David considered it a one-shot project. HBO head Chris Albrecht thought otherwise, asking David for a 13-episode series. David offered 10 episodes and a year commitment, but the response was largely positive, and the show entered its fifth season in 2007. For his efforts, David was nominated twice for an Emmy as Best Actor in a Comedy, and won two Producers Guild Awards and a Writers Guild Award – all for channeling a much more neurotic, uncomfortable version of himself.

David’s appearances outside of the two shows he was intimately involved in with were extremely rare. He had small roles in two Woody Allen pictures – “Radio Days” (1987) and “New York Stories.” He also appeared as himself on “Entourage” (HBO, 2004- ) and “Hannah Montana (Disney Channel, 2006- ); the latter was a favor to his daughters, who were fans of show.