The irony that the mayor of New York, Rudy Giuliani, is an opera buff escapes no one in this metropolis of nine million and counting. In the past year, his life has been playing itself out like a Wagnerian melodrama, and the only question left was when the fat lady would sing so the curtain could come down.

This week, Giuliani's estranged wife, Donna Hanover (though svelte), finally started to sing, and the giant sucking sound that was heard from Brooklyn to the Bronx was that of New Yorkers breathing a collective sigh of relief. "Everybody felt tremendous sympathy for Donna, and many women identified with her and the betrayal she suffered, so we understood why she had to take action," says feminist writer Anne Roiphe. "It was about damn time," sniffed one fed-up New York businesswoman.

In 1983, when the future mayor and first lady of New York married, friends described the pairing of the dashing district attorney and the TV news reporter as a modern-day fairytale. (Both previous marriages had ended in divorce.) Hanover herself said Giuliani swept her off her feet. In fact, once he became mayor (in 1993), he would prove highly adept at sweeping women off their feet, among them his press secretary, and more recently Judi Nathan, a drug company sales representative.

Though rumours swirled for years that the mayor was being unfaithful, Hanover always displayed behaviour more suited to the British upper classes than to revenge seeking New Yorkers, carrying out all public duties while acting the devoted wife and mother.

"Donna always fulfilled her official duties as Rudy's wife with tremendous class," says Linda Stasi, a columnist for the New York Post. "Whatever was going on in that marriage behind the scenes, she did what was required and gets incredibly high marks for grace under pressure."

But the charade finally imploded last year when the mayor, under pressure to explain why he was squiring Nathan around Manhattan instead of his wife, announced to the media that he and Hanover were separating. There was only one problem. He hadn't told Hanover.

Public outrage at the mayor's behaviour was palpable. "Can you imagine the humiliation?" Stasi says. "Your husband tells the world he is divorcing you, before he tells you?"

Hanover, though stunned, followed up quickly with her own statement, which in effect saw her acquiesce to the separation. "For several years it had become increasingly difficult to participate in Rudy's public life because of his relationship with one staff member," she said. "Beginning last May, I made a major effort to get us back together, and Rudy and I re-established some of our personal intimacies through the fall. At that point, he chose another path. Today's turn of events brings me great sadness. I had hoped to keep this marriage together."

It was a remarkably controlled speech, as Hanover had more than earned the right to return the favour and trash her husband in public. In fact, New Yorkers were hoping she would crucify the philandering mayor, but a TV personality and actress (a recent career change) to the core, she never lost her composure. In fact, the only thing she did that smacked slightly of revenge was accept an invitation to appear in a celebrity production of the Vagina Monologues. Her participation was seen as a passive-aggressive attempt to embarrass the mayor. (It worked, too.) But Hanover, an actress whose recent credits include The People vs Larry Flynt, Ally McBeal and Law and Order, said then, and still maintains, that the role was a simple career move to build up her CV.

One fact every New Yorker did assume was that Hanover would pack up her bags and her children - Andrew, 15, and Caroline, 11 - and storm out of Gracie Mansion, the mayor's official residence on Manhattan's Upper East Side. She didn't.

Yet, unlike another high-profile political spouse whose husband's dirty laundry was hung out in front of the country to dry, Hanover is no Hillary Clinton. Conventional wisdom suggested Hillary endured Bill's infidelities, starting 20 years ago in Arkansas, because she was a veritable Lady Macbeth, as power-hungry as he. And in fact, riding a wave of sympathy stemming from Monicagate, in November New Yorkers voted Hillary into the Senate.

By contrast, Hanover never displayed any keen interest in politics. Giuliani was the political animal, while she stuck happily to the sidelines, concentrating on raising her children and doing charity work. So her staying put in the mayor's mansion has nothing to do with a possible future power grab and everything to do with her children. "She wants to provide as much stability for them as she can," Stasi says and friends of Hanover confirm this.

MEANWHILE New Yorkers woke up in the following weeks to discover that they now had two first ladies. Hanover continued to host her own charity events, while Nathan started escorting Giuliani to parades, town hall meetings and city hall events. In fact, Nathan has attended so many public events as the mayor's consort in recent months that she has now acquired a $100,000 police security detail, courtesy of some very angry New York taxpayers. (Nathan was allegedly threatened on the street.) Hanover, meanwhile, still has her security detail and driver.

"New Yorkers now have an official mayor's wife and an official mayor's girlfriend, it's like something out of a Sicilian town," Stasi says. Adds Roiphe: "New York is a very tolerant city, but we didn't vote to have two first ladies, so I can't believe people approve. And to bring a new woman into the space where the previous woman lives [reports suggest Nathan has been staying at Gracie Mansion] is too much. It smacks of harem life."

Obviously Hanover thought so, too, which is why she instructed her lawyers last week to seek a restraining order against Nathan, barring her from entering the family home. Motions to keep extramarital relationships out of a primary family residence are not uncommon in the US. Judges often grant them, believing the presence of the "other woman" adds unwanted tensions and may hinder divorce negotiations.

The sticking point in this case is whether the mayor's mansion is public property or private residence. If a judge rules it is public property (and it is funded by taxes), Hanover may not be able to keep her nemesis away.

With Hanover finally throwing a punch after years of public bruising, New Yorkers, particularly women, have rallied to her side. Feminists who were angry that she did not simply walk out on the mayor were ecstatic to hear that she had marched into court to toss the other woman back on the street.

"Women strongly support what she did," Roiphe says. "Judi Nathan is Donna's successful rival, the woman who destroyed the marriage. And she is expected just to pass this woman in the living room?"

Stasi accompanied Hanover to court last week, then found herself, an hour later, at a lunch at Gracie Mansion that Hanover hosted for the charity Literacy Partners. Hanover, she says, was graceful and stoic throughout, until the editor of the New Yorker, David Remnick, made a speech. He said: "We are thrilled by Donna Hanover. I dare say we never had a first lady as contemporary, as smart, as personable as you. You've graced our city with your dignity. I would ask you all to stand and give thanks to the wonderful grace of this great lady."

The room stood. Hanover welled up in tears. This is one opera in which her husband might have starred, but she's singing the final aria.