He was most famous for who he loved.

Lucy.

But Desi Arnaz, who died yesterday of lung cancer at the age of 69, was a television pioneer in his own right -- a risk taker and an innovator whose influence on the medium extends beyond the fabulous success and longevity of the landmark situation comedy "I Love Lucy," still in reruns throughout the world more than two decades after it ceased production.

"Some people called it superficial, with no literary or intellectual values -- only escapism," Arnaz wrote in "A Book," his 1976 autobiography. "Okay, but I see nothing wrong with a show that is just that." Lucille Ball and Desi Arnaz, who were marriage partners and business partners throughout the decade, helped define the '50s for Americans and helped define television for all the years to come.

"The success of 'I Love Lucy' is something that only happens once in a lifetime, if you are fortunate enough to have it happen at all," Arnaz wrote at the conclusion of his book. "As for Lucy herself, all I can say is that I loved her very much and, in my own and perhaps peculiar way, I will always love her."

Yesterday, a spokesman for Ball said from Los Angeles she will attend Sunday's Kennedy Center Honors as scheduled -- she is one of this year's honorees -- after attending Arnaz's funeral tomorrow.

Interviewed in September, and asked about her reactions to the omnipresent "Lucy" reruns, Ball said of her ex-husband's role in shaping the program, "Desi was doing three jobs and doing them magnificently, and I marvel now when I think back." Ball's current husband, producer Gary Morton, said, "It's amazing what this man did. I look at that ingenuity there, it's fantastic."

Among other things, Arnaz, with cinematographer Karl Freund, invented the so-called three-camera technique still used in television today. The network had wanted "Lucy" to be live, but by insisting it be filmed, Arnaz saw to it the show would endure as well as prosper. Three cameras made it possible to film the show before a studio audience and record the sounds of real laughter.

There has seldom, before or since, been such laughter as this.

Lucy and Desi's 20-year marriage ended in divorce as the '50s, and "I Love Lucy," were shutting down; both later remarried. Of all the decade's celebrity couples, they may have been the most public. An episode of "I Love Lucy" in which Lucy Ricardo gives birth to a son aired on the very day, Jan. 19, 1953, that a son was born to Lucy and Desi in real life.

That episode, "Lucy Goes to the Hospital," attracted the biggest single audience ever to watch a television program up to that time. It earned a 71.8 Nielsen rating and 92 share, meaning nearly three-quarters of the TV sets in America were tuned to CBS to see it. For the 1952-53 season, "I Love Lucy" averaged a 67.3 rating, the highest ever. By comparison, today's biggest hit, "The Cosby Show," averaged a 34.3 last season.

There were 11 million TV households in the United States when "Lucy" premiered in 1951, and 45 million when it signed off a decade later. Everything had changed, and yet "I Love Lucy" would never be off the air.

Originally, CBS Chairman William S. Paley didn't want Arnaz to be part of the package. It was Ball who insisted that her real-life husband play her husband on the show. Arnaz earned the respect of CBS when, while going over budgets for the second season, he discovered the network had mistakenly allocated $ 1 million too much. No one else had noticed the error.

"That changed CBS' opinion of him," according to Bart Andrews, author of "The I Love Lucy Book." From Hawaii yesterday, Andrews said of Arnaz, "The bottom line is people will remember him as a second-rate actor in a hit show and as Mr. Lucille Ball. In fact he was much more than that. He was a real pioneer in television and he helped make the medium what it is today."

Andrews said he interviewed Arnaz for his book eight times from 1975-77. "He was not jolly at all. Neither was Lucy. These were pretty serious people," Andrews recalled. "He was very sentimental, though. Whenever we got into a heavy subject about 'I Love Lucy,' he was sort of crying. He broke down a few times and had to leave the room when we talked about Lucy, who I think he still loved to this day."

"I Love Lucy" blossomed into an empire for Mr. and Mrs. Arnaz. When they agreed to work for only $ 4,000 a week instead of $ 5,000 that first season, Arnaz stipulated that they would own the shows outright, not just 50 percent of the rights, as first proposed. In 1957, CBS bought back those rights from Lucy and Desi for $ 5 million.

The couple bought the studio, RKO, where they had first met in 1940, and under Arnaz's supervision turned out such hits as "The Untouchables," "Our Miss Brooks" and "December Bride." From the anthology series "Desilu Playhouse" came the pilots for such series as "Mission: Impossible" and "The Twilight Zone."

As an actor, Arnaz's contribution to "I Love Lucy" was substantial. He was an uncommonly colorful foil, and his fracturing of the English language proved one of the show's most durable sources of humor. A longtime song-and-dance man, he performed numbers like "Babalu," his trademark tune, "I'll See You in C-u-b-a" and other pop hits from, or about, his native Cuba.

But he also developed real skills as a comic actor, and even played the rare serious scene. His longest time on screen without Lucy, about five minutes, occurred in a 1954 episode called "Ricky Minds the Baby" in which Arnaz touchingly recites "Little Red Riding Hood," in Spanish, to his infant son.

In his book, Arnaz conceded that all was not harmonious on the "I Love Lucy" set. William Frawley and Vivian Vance, who played neighbors and landlords Fred and Ethel Mertz, detested one another. Frawley, according to Arnaz, would refer to Vance with terms like "bitch," "silly broad" and "fat-ass." Vance told associates no one would believe she could be married to "that old goat." Meanwhile, the Arnaz marriage was legendary, even in hot-tempered Hollywood, for its tumultuousness. In recent interviews, Ball said she divorced Arnaz because of his repeated and flagrant acts of infidelity.

She also said they were still friends.

On the air, none of the hostilities were even vaguely apparent. It was a love story America dearly loved. "I love Lucy and she loves me; we're as happy as two can be," Arnaz sang to his wife on one program, adding lyrics to the familiar title tune. "Sometimes we quarrel but then, how we love making up again!"

In his later years, Arnaz was ill and, reportedly, lonely. He told the Kennedy Center he would have attended Sunday's gala, in which his ex-wife will be the first pure television personality to be honored, but that his poor health prevented him. His doctor said he had smoked too many Cuban cigars.

Trying to analyze the enormous and lasting appeal of "I Love Lucy" in his book, Arnaz wrote, "I am sure there have been occasions when you had a great time at a party for no particular reason. Why did you? The chemistry, the mixture of the people there, made it fun." The host has left the party, but it goes on. Perhaps forever. Who Lucy loved will be remembered, too.