June 2, 2008: More than one million signatures are submitted for a ballot measure that would amend the state Constitution to define marriage as a union "between a man and a woman" and undo the California Supreme Court ruling allowing gay marriages.
June 16, 2008: County registrars and clerks in Los Angeles, San Francisco, Alameda, Sonoma and Yolo counties keep offices open to allow at least two dozen same-sex couples the distinction of being among the first to wed. Seven Southern California Roman Catholic bishops, including L.A. Cardinal Roger Mahony, reaffirm their opposition to same-sex marriage.
July 16, 2008: The California Supreme Court rejects arguments that Proposition 8 -- which if passed by voters would amend the state Constitution to ban gay marriage -- is an illegal constitutional revision. Justices also reject the argument that voters had been misled when they signed petitions to put it on the ballot.
Nov. 4, 2008: California voters pass Proposition 8 -- which amends the state Constitution to ban gay marriage -- with about 52% of the vote. A 2000 ballot initiative banning gay marriage, Proposition 22, had passed with 61% of the vote but was later struck down by the state's high court.
Nov. 19, 2008: The California Supreme Court votes 6 to 1 to review legal challenges to Proposition 8, but refuses to permit gay weddings to resume pending a final decision.
Mar. 2, 2009: The California state Senate approves a resolution calling Proposition 8, the voter-approved ban on gay marriage, an improper revision of the California Constitution because it was not approved by the Legislature.
Mar. 5, 2009: The California Supreme Court strongly indicates it will rule that Proposition 8 validly abolished the right for gays to marry but will allow same-sex couples who wed before the November election to remain legally married.
May 26, 2009: The California Supreme Court upholds Proposition 8's ban on same-sex marriage but also rules that gay couples who wed before the election will continue to be married under state law. The decision virtually ensures another fight at the ballot box over marriage rights for gays. Gay rights activists say they may ask voters to repeal the marriage ban as early as next year, and opponents have pledged to fight any such effort. Proposition 8 passed with 52% of the vote.
May 27, 2009: Opening a new front in California's gay marriage battle, prominent attorneys working for a project of the American Foundation for Equal Rights announce they will file suit in federal court. The suit calls for an injunction against Proposition 8 and the immediate reinstatement of marriage rights for same-sex couples.
Oct. 14, 2009: A federal judge refuses to dismiss a constitutional challenge to Proposition 8, ruling the voter-approved ban on same-sex marriage raised legal and factual issues that required a trial.
Aug. 4, 2010: A federal judge in San Francisco rules that gays and lesbians have a constitutional right to marry, striking down Proposition 8, the voter approved ballot measure that banned same-sex unions. U.S. District Chief Judge Vaughn R. Walker said Proposition 8, passed by voters in November 2008, violated the federal constitutional rights of gays and lesbians to marry the partners of their choice.. His ruling is expected to be appealed to the U.S. 9th Circuit Court of Appeals and then up to the U.S. Supreme Court.
Aug. 12, 2010: U.S. District Judge Vaughn R. Walker keeps same-sex marriages on hold for at least another week.
Aug. 16, 2010: A three-judge panel of the U.S. 9th Circuit Court of Appeals decides to put same-sex marriage in California on hold.
Jan. 4, 2011: A panel of federal appeals court judges seeks input from the California Supreme Court on the right of private groups to defend the ban on gay marriage.
Feb. 16, 2011: The California Supreme Court decides to rule on whether sponsors of ballot initiatives have legal standing to defend the measures in court.
Mar. 23, 2011: Gay marriages will not resume while the U.S. 9th Circuit Court of Appeals decides the constitutionality of Proposition 8's ban on same-sex marriage.
July 28, 2011: The legal battle over Proposition 8 will go before the California Supreme Court on Sept. 6. The justices will then have 90 days to decide whether state law gives proponents of ballot measures legal standing to defend them in court.
Sept. 6, 2011: The California Supreme Court appears ready to rule that the backers of Proposition 8 and other ballot measures have the right to defend them in court.
Nov. 17, 2011: The California Supreme Court rules that the sponsors of Proposition 8 and other ballot measures are entitled to defend them in court when the state refuses to do so, a ruling likely to spur federal courts to decide the constitutionality of same-sex marriage bans.
Feb. 7, 2012: A federal appeals court strikes down California's ban on same-sex marriage, clearing the way for the U.S. Supreme Court to rule on gay marriage.
June 5, 2012: The U.S. 9th Circuit Court of Appeals votes not to review a three-judge panel's decision to overturn the voter-approved 2008 state constitutional amendment. The legal battle is now headed to the U.S. Supreme Court, the final chapter in four years of litigation over the constitutionality of Proposition 8's ban on gay marriage.
July 31, 2012: Opponents of same-sex marriage ask the U.S. Supreme Court to overturn a federal appeals court decision that struck down Proposition 8, the 2008 California ballot initiative that limited marriage to a man and a woman.