Feb. 12, 2004: San Francisco Mayor Gavin Newsom authorizes the county clerk to begin issuing marriage licenses to same-sex couples. Del Martin and Phyllis Lyon are the first to marry.

Feb. 13: Two conservative groups sue to stop the marriages, charging that Newsom acted illegally in authorizing licenses.

Feb. 25: Three San Francisco residents ask the state Supreme Court to put an immediate halt to the weddings.

Feb. 27: Attorney General Bill Lockyer asks the state Supreme Court to stop San Francisco officials from issuing same-sex marriage licenses and invalidate gay and lesbian weddings that have taken place at City Hall since Feb. 12.

March 11: The California Supreme Court orders an immediate halt to same-sex weddings in San Francisco and says it will decide later in the year whether Newsom exceeded his authority in allowing the marriages.

March 11: San Francisco responds by suing the state in Superior Court, contending that California's ban on same-sex marriage is unconstitutional.

March 12: Six unwed gay and lesbian couples file suit in Superior Court, challenging the state's marriage law on constitutional grounds. The suit is later consolidated with the city's.

May 25: California's Supreme Court justices hear arguments on the legality of San Francisco's same-sex marriages.

July 15: The U.S. Senate defeats the Bush administration's proposed constitutional amendment to ban same-sex marriage.

Aug. 12: The California Supreme Court rules that Newsom exceeded his authority when he authorized same-sex marriages in San Francisco and voids 3,955 marriages that were recorded between Feb. 12 and March 11.

March 14, 2005: San Francisco Superior Court judge rules California law defining marriage as the union of a man and a woman violates guarantees of equality and fundamental rights in the state Constitution.

April 4: A state appeals court panel upholds California's domestic partner law.

Sept. 29: Gov. Arnold Schwarzenegger vetoes a bill to give same-sex couples the right to marry.

Oct. 5, 2006: State appeals court rules gays and lesbians have no constitutional right to marry in California, and any change giving them that right must come from state lawmakers or the voters rather than the legal system.

Nov. 13: The city of San Francisco appeals to the state Supreme Court to review the constitutionality of California's ban on same-sex marriage and rule that the law violates the rights of gays and lesbians.

Sept. 7, 2007: For a second time in three years, the Legislature approves a bill to give same-sex couples the right to marry in California. Schwarzenegger later vetoes it.

March 4, 2008: California Supreme Court hears arguments about same-sex marriages during a 3 1/2-hour hearing.

April 24: Supporters of an initiative to ban same-sex marriage in the state's Constitution submit more than 1.1 million signatures to qualify the measure for the November ballot.

May 15: California Supreme Court overturns the same-sex marriage ban on a 4-3 vote.

June 3: Proposition 8, a constitutional amendment to ban gay marriage, qualifies for the November ballot.

Nov. 4: Prop. 8 passes with 52 percent majority.

May 22, 2009: Lawsuit filed in federal court seeks to overturn Prop. 8.

Jan. 11, 2010: The federal trial on Prop. 8 begins.

June 17: Final arguments made in federal court; the case is in the hands of judge.

Aug. 4: Chief U.S. District Judge Vaughn Walker rules Prop. 8 is unconstitutional, but issues a stay on the ruling pending further hearings.