Her partner of more than 55 years and wife of just over two months, Phyllis Lyon, was with her.

"Ever since I met Del 55 years ago, I could never imagine a day would come when she wouldn't be by my side," Lyon, 83, said in a statement Wednesday.

"I also never imagined there would be a day that we would actually be able to get married," she added. "I am devastated, but I take some solace in knowing we were able to enjoy the ultimate rite of love and commitment before she passed."

Martin and Lyon exchanged vows at San Francisco City Hall on June 16, the first day same-sex couples could legally wed in California, after being together for more than half a century.

Mayor Gavin Newsom, who officiated the wedding, singled them out to be the first gay couple to be declared "spouses for life" in the city in recognition of their long relationship and their status as pioneers of the gay rights movement.

"The greatest way we can honor the life work of Del Martin, is to continue to fight and never give up, until we have achieved equality for all," Newsom said Wednesday.

The couple, who in 1955 co-founded the nation's first outspoken advocacy group for lesbians, Daughters of Bilitis, similarly served as the public faces of the marriage debate four years earlier, when Newsom in 2004 challenged California's one man-one woman marriage laws by directing city officials to issue licenses to gay and lesbian couples. Their marriage, along with those of almost 4,000 other couples, were invalidated later by the California Supreme Court.

The action laid the groundwork for a series of lawsuits that ultimately led a 4-3 majority of the same court on May 15 to strike down the state's gay marriage ban. Martin and Lyon were two of the original plaintiffs.

"We would not have marriage equality in California if it weren't for Del and Phyllis. They fought and triumphed in many battles," said House Speaker Nancy Pelosi of San Francisco. "Through it all, their love and commitment to each other was an inspiration to all who knew them."

An imposing and uncompromising figure, Martin in 1970 wrote an influential article for the Advocate magazine that criticized what she saw as the gay rights movement's persistent chauvinism. The schism, which mirrored the increasing cultural influence of the women's movement, eventually prompted Lyon and Martin to adopt feminism and racism among their causes.

Trained as journalists, they together wrote "Lesbian/Woman," a landmark 1972 book in which they tried to make the point that lesbians should be seen for more than their sexuality and simultaneously offered a frank, no-nonsense account of lesbian relationships.

A year later, Martin became the first out lesbian to serve on the board of directors of the National Organization for Women, a position she won despite opposition within the feminist organization. Critics in the group feared the impact of having a leader that many in the mainstream still viewed as socially deviant.

Born as Dorothy Taliaferro on May 5, 1921, in San Francisco, Martin acquired the surname she would use the rest of her life from her four-year marriage to her college sweetheart, James Martin. They had a daughter, Kendra, before they divorced.

In "Lesbian/Woman," Martin recounted that the growing realization that she was attracted to women initially sparked thoughts of suicide. She eventually worked through her feelings despite the discrimination and threat of arrest gay people faced during the conservative 1950s.

When she started working for a construction trade publication in Seattle, she carried a briefcase without worrying whether it made her appear manly. The briefcase was the first thing Lyon noticed about her future spouse, she always recounted in stories about how the two met.

"Ultimately, it gets down to self-acceptance. If you accept yourself, you don't give a damn what anyone else thinks," Martin said in "No Secret Anymore: The Times of Del Martin and Phyllis Lyon," Joan Biren's 2003 documentary about the couple.

Martin is survived by Lyon; her daughter, Kendra Mon, a son-in-law, two grandchildren and her sister-in-law.

In Martin's honor, Newsom ordered the American flags at City Hall and the rainbow flag in the Castro District, the heart of the city's gay and lesbian community, to be flown at half-staff until sundown Thursday. Plans for a public memorial are pending.