The Vatican on Friday named Salvatore Cordileone as Archbishop of San Francisco.

Pope Benedict XVI's appointment of Cordileone, who has served as Bishop of Oakland since 2009, was announced in a statement released Friday morning.

“I'm humbled by the confidence that Pope Benedict XVI has placed in me by entrusting to me the pastoral care of the Archdiocese of San Francisco,” said Cordileone during a press conference.

“I am pleased to welcome Archbishop-elect Cordileone,” said outgoing Archbishop George Niederauer, who has served in the post since December 2005. “And to assure him of our prayers, loyalty, support and cooperation, as well as our friendship and affection.”

Cordileone played an instrumental role in passage of Proposition 8, California's gay marriage ban.

In 2008, Cordileone, then bishop of San Diego, reached out to help raise $1.5 million to get the measure on the ballot. He also organized leading evangelical Christian leaders, such as the Rev. Jim Garlow of Skyline Church, to back the amendment.

After passage, he told a Catholic radio show that “the ultimate attack of the Evil One is the attack on marriage.”

Assembly Tom Ammiano, who is openly gay, told the San Francisco Chronicle: “This isn't a marriage made in heaven.”

The gay rights group GetEqual on Sunday will demonstrate against the appointment in front of Oakland's Cathedral of Christ, where Cordileone currently serves as bishop.

(Relate: Pope Benedict elevates anti-gay marriage Timothy Dolan to Cardinal.)