The funeral of Brooke Astor, the philanthropist and socialite who died Monday at the age of 105, united more than 900 New Yorkers in mourning yesterday afternoon at Saint Thomas Church, on Fifth Avenue at 53rd Street.

Astor, known during her life for harboring contempt for pretension, made specific arrangements more than a decade ago to have a regular Episcopal funeral service. The event, however, was far from ordinary, as Astor’s prominent friends and city leaders remembered a life of wealth, fashion, and philanthropy, anchored in the upper echelons of Manhattan society.

Mourners and photographers began lining the steps of the church an hour and a half before the funeral began at 2:30 p.m., and about 200 onlookers packed the street, peering at the well-heeled attendees, dressed in stylish hats and summer suits in khaki, off-white, and brown. Passersby said they thought a wedding was in progress.

About 400 invitees entered through the church’s main entrance on Fifth Avenue, and sat in the first set of pews; the public entered at 53rd Street.

“She saw history from a perspective few of us can share,” Mr. Bloomberg said during his tribute to Astor. She was “there as electric lights replaced gas lights, and horse-drawn carriages gave way to automobiles.”

She always wore “a pretty hat as though she were calling on the queen of England, who she knew quite well,” a close friend of Astor, David Rockefeller, said at the funeral. She was “our one and only leading lady,” he said.

Mr. Bloomberg and Astor served together on the board of the Metropolitan Museum of Art, he said, and once shared a lunch in her apartment. He was struck by her “warmth and wit,” he said.

“I have seen her captivate, on the one hand, a member of the British royal family, who I had introduced to her, with a stunning remark: I am 95, sir, and never had a facelift,” the church’s rector emeritus, Canon John Andrew, said in the homily, “and on the other, be taken by a great, big Afro-American janitor at the Metropolitan Museum, taken into his arms in a loving embrace as she got out of the car. And, my god, did she return that embrace.”

Astor, who reportedly gave away about $200 million during her life, donated to scholarly institutions such as the New York Public Library, as well as to the city’s parks, gardens, and public housing.

Astor last summer made headlines as she became embroiled in an ugly court battle. Her grandson, Philip Marshall, filed a court petition against his father and Astor’s only son, Anthony Marshall, alleging that he neglected and mistreated Astor in her final years.

Anthony Marshall, 83, denied the charges, and yesterday his voice cracked as he read a note that his mother wrote to be delivered at her funeral: “When I go from here, I want to leave behind me the world richer for the experience of me. I want the creatures and the animals and the birds to be a little less afraid of human beings,” he said. “Death is nothing and life is everything…. I want to leave behind me a deeper sense of God.”

“New York and her many friends have lost a wonderful person, and I have lost my mother,” Mr. Marshall said, before breaking down in tears. The service ended with a bagpipe rendition of Amazing Grace, as mourners walked out into a gray city filled with rain.

Mayors Koch, Dinkins, and Bloomberg followed the family members as they walked from the church. The ushers included the president of the Alliance for the Arts, Randall Bourscheidt; a patron of the arts, Barbara Fleishman; the president of the New York Public Library, Paul LeClerc; the president of the New York Botanical Garden, Gregory Long; an investment banker, Frederick Melhado; a philanthropist, Howard Phipps; television journalist Charles Rose, and a real estate investor, Elihu Rose.

Eight United State marines served as pallbearers in acknowledgment of Astor’s father, Major General John Russell, who served as the 16th Commandant of the U.S. Marine Corps.