(CNN) Activist Phyllis Lyon, who spent more than 50 years fighting for LGBTQ rights, died of natural causes. She was 95.

California Gov. Gavin Newsom shared the news of Lyon's death in a post on Twitter on Thursday, calling her a "dear friend."

When Newsom served as mayor of San Francisco, he officiated the wedding between Lyon and her late partner Del Martin in 2008.

In 2004, San Francisco officials allowed gay couples in the city to wed, prompting a flood of applicants to the City Hall clerk's office. The officials chose Lyon, then 80, and Martin, then 83, to take the first vows.

Those unions were voided by California's Supreme Court, until 2008 when it struck down the state's ban on same-sex marriage. The ruling paved the way for same-sex couples to marry in the state -- and Lyon and Martin chose to get remarried.

Read More