1930s: Soap operas first begin airing on the radio with WGN’s “Painted Dreams,” a 15-minute soap about an Irish-American widow and her daughter. By the time World War II began, there were 64 soaps airing on the radio.

1937: “Guiding Light,” the longest running soap, debuts on the radio.

1946: “Faraway Hill” is the first soap to air on television. The serial ran for three months on the Dupont Television Network and was about a widowed New Yorker who moves to a small town to be closer to her relatives.

1948: The 10 highest-rated daytime programs are all soaps, and of the top 30 daytime shows, all but five are soaps.

1952: “Guiding Light” first airs on television in daily, 15-minute episodes. Since it first aired, the show has taken place in three different locales: the fictional towns of Selby Flats and Five Points, and the current locale of Springfield, USA.

1956: “As the World Turns” becomes the first half-hour serial. Behind “Guiding Light,” it’s the second longest-running soap. Over the years, the soap starred Marisa Tomei, Meg Ryan, Julianne Moore and Jason Biggs before they became movie stars. “ATWT” also changed the way soaps were done - it expanded the number of characters, slowed the pace with which a story was told and used multiple cameras.

1960: The last network radio soap opera goes off the air.

1963: “General Hospital” hits the airwaves at ABC. It became one of the first soaps to earn ratings on par with those of CBS daytime serials, which dominated the landscape. (Before they were stars: Demi Moore, Rick Springfield, John Stamos and Ricky Martin.)

1964: “Another World” debuts on CBS. During its first year, one of the characters has an illegal abortion - the first time a daytime soap opera had dealt with the topic.

1965: “Days of Our Lives” begins airing on NBC.

1966: ABC starts airing episodes of “Dark Shadows,” a daytime soap about a 200-year-old vampire. It was canceled after five years.

1968: Now a legend in the soap world, Agnes Nixon creates “One Life to Live” for ABC. Nixon became known for tackling complex social issues in her shows, such as when a “OLTL” character became a drug addict and was sent to a real-life treatment center in New York, where the character interacted with actual patients. (Before they were stars: “Superman Returns’” Brandon Routh, Ryan Phillippe and Tommy Lee Jones.)

1970: Another Agnes Nixon show, “All My Children,” begins its run on ABC and stars a young Susan Lucci, who is still with the show today. The show became the first soap to write the Vietnam War into one of its plots. (Before they were stars: Sarah Michelle Gellar, Lauren Holly, Kelly Ripa and Josh Duhamel.)

1973: “The Young and the Restless” debuts on CBS. Since 1988, it has consistently been one of the highest-rated soap operas. (Before they were stars: David Hassellhoff, Tom Selleck and Eva Longoria.)

1975: Soap Opera Digest magazine is founded. By 1990, it had a circulation of 850,000 and claimed a readership of 4 million. Soap Opera Digest and other magazines like it offer plot synopses of all current soaps, as well as actor profiles and letters-to-the-editor columns.

1976: “Days of Our Lives” and “Another World” become the first soaps to be expanded to an hour (“Another World” was even 90 minutes for a time). One by one, other soaps follow suit. Also in 1976, the first TIME cover devoted to soap operas hit newsstands. The cover featured Bill Hayes and Susan Seaforth Hayes from “Days of Our Lives,” and the headline read “Soap Operas: Sex and suffering in the afternoon.”

1978: “All My Children” becomes the first soap to have an exotic location shoot, sending some of its actors to St. Croix. Also in 1978, “Dallas” becomes the first primetime soap to hit network TV.

1980s: Soap operas begin telling action-adventure storylines. During the next decade, “General Hospital’s” Luke and Laura saved the world from being frozen and helped a princess find her treasure in Mexico, while youngster Robin befriended an alien. During this time, soaps also began putting together supercouples such as Luke and Laura, Bo and Hope (“Days of Our Lives”) and Victor and Nikki (“The Young and the Restless”).

1981: “General Hospital’s” Luke and Laura tie the knot in front of guest star Elizabeth Taylor and 30 million viewers, the highest daytime TV ratings ever recorded.

1984: Daytime’s first black supercouple, “All My Children’s” Angie and Jesse, are introduced.

1987: “The Bold and the Beautiful,” the only remaining half-hour soap, starts airing on CBS. The action focuses on rival Los Angeles fashion houses, Forrester Creations and Spectra Couture.

1988: “As the World Turns” introduces the first gay male character, Hank Elliot, in daytime TV.

1989: “All My Children” character Cindy Parker, one of the first soap characters to have AIDS, dies.

1990s: Soap opera writers begin focusing on younger characters, as well as social issues, like drug addiction, alcoholism, multiple personalities and AIDS.

1993: Maurice Benard joins the cast of “General Hospital” as mob boss Sonny Corinthos. Over the years, the show’s focus has increasingly been on Corinthos, his dirty business dealings and his romantic entanglements.

1995: Stone Cates, a character on “General Hospital,” contracts AIDS, transmits the HIV virus to his girlfriend, Robin, and dies.

1997: The two-hour pilot of “Port Charles,” a spin-off of “General Hospital,” airs on primetime TV. The show runs until 2003, when ABC cancels it.

1998: ABC airs primetime episodes of both “General Hospital” and “One Life to Life.”

1999: CBS cancels “Another World.” It was later replaced with “Passions,” which was created by “Days of Our Lives” writer James E. Reilly. Also in 1999, Susan Lucci finally wins a Daytime Emmy Award after being nominated 18 times.

2000: SOAPnet, a network that airs both current and past soap operas, is born. At first, the net only showed ABC soaps, but later expanded to ones airing on other networks. Original programming includes “Soap Talk,” “I Wanna Be a Soap Star” and “Soapography.”

2000: Actress Eden Riegel’s Bianca Montgomery comes out to her mother, Erica Kane, on “All My Children.” Bianca becomes the first lesbian character on a daytime soap.

2005: William J. Bell, creator of both “The Young and the Restless” and “The Bold and the Beautiful,” dies.

Coming in 2006: CBS will air the 15,000th televised episode of “Guiding Light.”

Sources: www.wikipedia.com, www.soapcentral.com, www.imdb.com, The Museum of Broadcast Communications