HBO celebrates forty years of sex, violence and... Fraggles

HBO became a household name in the UK with the advent of The Sopranos in 1999, which ushered in a golden decade of TV drama. Since then, its Pavlovian, pre-episode fuzzy-screen ident has become a reassuring mark of quality. HBO boasts about 30 million subscribers in the US, and countless more viewers in this country and elsewhere thanks to DVD box-sets, Sky Atlantic and internet piracy. Yet this month the premium cable channel – one of the few in the US able to broadcast with swearing and sex, and without ad breaks – celebrates its 40th birthday, which means there are 27 years of pre-Sopranos unaccounted for.

When the channel first reached screens in 1972, its inaugural broadcast was the film adaptation of Ken Kesey's novel Sometimes A Great Notion, starring Henry Fonda and Paul Newman as members of an Oregon logging clan. That was followed by an ice hockey game, shown live from Madison Square Garden. When Time-Life (later Time Warner) launched HBO, the company envisaged it not as a home for original programming so much as for pay-per-view movies and sports. During the 1970s the cable TV industry grew slowly, due in part to the powerful television networks, which feared competition and encouraged federal regulations to limit its spread.

In 1975, HBO broadcast the so-called "Thrilla in Manila" confrontation between Muhammad Ali and Joe Frazier. The channel turned its first profit two years later, and in 1980 it launched a second, cheaper movie channel, Cinemax, to compete with its own pay-per-view rival, Showtime (which now produces Homeland and Dexter). In 1982, with Columbia Pictures and CBS, it established a new Hollywood movie studio, Tri-Star. Despite its success, however, HBO was still known by some frustrated subscribers for simply showing the same movies over and over again.

In 1983, it broadcast its first made-for-pay-TV movie, The Terry Fox Story: the true story of a Canadian amputee-runner and cancer activist. It also showed its first children's show, Jim Henson's Fraggle Rock, which later moved to the specialist channel, HBO Family, as the broadcaster diversified.

Now HBO is the umbrella name for a collection of channels, and famous for a selection of genres. Among its celebrated documentaries is Spike Lee's four-part epic of Hurricane Katrina, When The Levees Broke (2006). It also cultivated a reputation for comedy, with its one-off stand-up specials, and its annual Young Comedians Show, first broadcast in 1976. From 1992 to 1998, HBO's most ground-breaking programme was The Larry Sanders Show, a super self-aware behind-the-scenes comedy about a late-night talkshow.

In 1997, HBO broadcast the first series of its first hour-long drama serial, the prison-set Oz. The same year, HBO earned 90 Emmy nominations, the first time a cable channel had garnered more nominations than any broadcast network. The rest – The Sopranos; The Wire; Six Feet Under; Deadwood; Sex And The City; Entourage; True Blood; Girls; Boardwalk Empire; Game of Thrones; Curb Your Enthusiasm – is history.