Openly lesbian Annise Parker was sworn in as mayor of Houston on Saturday.

Surrounded by about two dozen close friends and family members, Parker became Houston's 61st mayor in a private ceremony officiated by longtime friend Judge Steven Kirkland. Parker's partner, Kathy Hubbard, held the family bible used to administer the oath, CultureMap Houston reported.

Houston is the largest city in the nation to endorse an openly gay mayor. With a half-million residents, Portland, Oregon previously held the title, electing openly gay Mayor Sam Adams last year. Houston, however, only trails behind New York, Los Angeles and Chicago.

Parker, 53, seized 53.6 percent of the vote in a December 12 runoff election to best her opponent, Gene Locke, an African-American lawyer and former city attorney. Anti-gay rhetoric marred the campaign's final lap as social conservatives and religious leaders attempted to make sexual orientation an issue in the contest.

“This election has changed the world for the gay, lesbian, bisexual and transgender communities, just as this election is about transforming Houstonians' lives for the better,” Parker said in a statement released shortly after her victory.

A public swearing in ceremony will take place on Monday, but the city charter mandates the mayor be installed on January 2. On Monday, U.S. District Judge Vanessa Gilmore will ceremoniously swear in Parker, who will then swear in the 14-member city council. A free concert headlined by Jennifer Holliday will take place at 6PM.