Del Martin (left) and her partner Phyllis Lyon, being married by Gavin Newsom.

Her wife, Phyllis Lyon was at her side when she passed away.

At a meeting of the LGBT caucus at the Democratic National Convention, Gavin Newsom, his voice breaking, said he had just heard of her death. “Del Martin and Phyllis Lyon defined love, devotion and constancy,” he said.

A statement released later from Barack Obama said:  “Michelle and I were deeply saddened to hear that Del Martin had passed.  Del committed her life to fighting discrimination and promoting equality.  Our thoughts and prayers go out to her spouse Phyllis Lyon, and all those who were touched by her life.”

Martin began working as an activist after receiving her degree in journalism from the University of California at Berkeley. While working on a newspaper in Seattle, Martin met her partner Phyllis Lyon and the two began working on behalf of lesbians in their community.

Martin and Lyon devoted their lives to working towards LGBT equality, healthcare access, advocacy on behalf of battered women, and issues facing elderly Americans. Their many contributions over the past five decades helped shape the modern LGBT movement.

Her last public political act, on June 16, 2008, was to marry Phyllis Lyon, her partner of 55 years. They were the first couple to wed in San Francisco after the California Supreme Court recognized that marriage for same-sex couples is a fundamental right in a case brought by plaintiffs including Martin and Lyon.

“Today the LGBT movement lost a real hero,” Kate Kendell, Executive Director of the National Center for Lesbian Rights said in a statement.

“For all of Del’s life, she was an activist and organizer even before we knew what those terms meant. Her last act of public activism was her most personal—marrying the love of her life after 55 years. In the wake of losing her, we recognize with heightened clarity the most poignant and responsible way to honor her legacy is to preserve the right of marriage for same-sex couples, thereby providing the dignity and respect that Del and Phyllis’ love deserved.”

“The lesbian, gay, bisexual and transgender community has lost one of its bravest and most admired activists,” said HRC President Joe Solmonese.

“Del Martin dared for decades to fight to marry her beloved Phyllis, and by doing so became an iconic hero the LGBT community. Her death is a great loss to all of us, but her life is an inspiration,” Solmonese said.

In 1955, Lyon and Martin were among the founders of the Daughters of Bilitis, the first lesbian rights organization.

In 1956, they launched “The Ladder,” the first lesbian newsletter, which became a lifeline for hundreds of women isolated and silenced by the restrictions of the era. Del Martin was the first openly lesbian woman elected to the board of the National Organization of Women (NOW), and in 1971, encouraged the board to pass a resolution stating that lesbian issues were feminist issues.

Del Martin’s publication of Battered Wives in 1976 was a major catalyst for the movement against domestic violence. Martin became a nationally known advocate for battered women, and was a co-founder of the Coalition for Justice for Battered Women in 1975.

Martin lectured at colleges and universities around the country. Martin received her doctorate from the Institute for Advanced Study of Human Sexuality in 1987.

In 1995, Martin and Lyon were named delegates to the White House Conference on Aging by Senator Dianne Feinstein and Congresswoman Nancy Pelosi. In 2004,

“Del lived her life with great compassion, wit, tenacity, generosity, and valor,” said The Honorable Donna Hitchens, Founder of the National Center for Lesbian Rights.

“She inspired thousands of us to be more courageous and energetic than we thought possible. When faced with moments of fatigue, laziness or weakness, one had only to ask – ‘What would Del and Phyllis do?’ While she will be greatly missed, her legacy will be cherished forever.”

Martin is survived by her spouse Phyllis Lyon, daughter Kendra Mon, son-in-law Eugene Lane, granddaughter Lorraine Mon, grandson Kevin Mon, sister-in-law Patricia Lyon and a vast, loving and grateful lesbian, gay, bisexual and transgender family.

A public memorial and tribute celebrating the life of Del Martin will be planned in the next few weeks.