Christina Patterson: The Queen did her duty... and they loved her for it

In the end, she smiled. In the end, after a long service, and a long lunch, and a very, very long weekend of standing around in the cold and the rain, when she walked out on to the balcony, and waved at her subjects, and watched an awful lot of planes fly in complicated patterns over her home, the second-longest-serving monarch in British history smiled.

She didn't smile all that much at the concert at Buckingham Palace the night before. She looked, in fact, as if sitting through lame jokes from nervous comedians, and slightly shaky performances from young pop stars she'd never heard of, and even more shaky performances from pop stars now collecting their pensions, wasn't necessarily the thing she'd have chosen to do on the night she heard that her husband of 65 years had been taken ill.

But for the Queen, sitting through concerts, and shaking hands, and making small talk, and making more small talk, and making yet more small talk, to people she'll never meet again, who will remember that small talk for ever, isn't about having fun. For the Queen, it's about a promise she made on her 21st birthday, and renewed 60 years ago, on the death of her father.

And this, more than anything, is why people love her. "No day of her life has ever been her own," said Samantha Hope, a civil servant I met in the ticket hall at St Paul's Tube station. "That sense of duty, day in, day out." She had, she said, won one of three pairs of tickets for the Diamond Jubilee service at St Paul's allocated in a draw to MoD staff around the country. Like Nancy Velasquez, a Colombian married to an electrician who worked at St Paul's, and Ruth Luckman, an office manager at the cathedral, who both stood out from the crowds on the Tube in their smart jackets and hats, she was thrilled to be included in the official celebrations. "I think," she said, "it has been quite dignified, which is just what was wanted: to celebrate, but not go over the top".

Certainly, there was very little that seemed "over the top" in the long queue of guests that snaked from the side entrance of St Paul's, round Paternoster Square and down an alleyway. They were in suits, and frocks, and hats, and heels: the standard fare of palace garden parties or posh weddings. Away from the queue, in the crowds building up next to the barriers around the front steps of the cathedral, where, four months ago, people tried to bring down capitalism by sleeping in tents, most were in the kind of leisurewear you'd be hard-pressed to describe as "smart".

There were flags. Of course there were flags. There were flags sold at the Tube, and flags given out by newspapers and magazines, and flags on bags and hats. And then there were the people who thought one flag wasn't enough. People like Susan Simm, a post office clerk from Warrington, who was wearing Union Flag earrings and badges and scarf and shoes. Her daughter, Sarah Wilmott, was wearing them, too. "We're big fans of the Queen," they said, perhaps unnecessarily. "My friends," said Susan, perhaps also unnecessarily, "think I'm a bit mad".

Warrington, it turned out, was just a hop away compared with the journeys quite a few of the people I spoke to had made. John MacNaughton had come from Brisbane. "In Australia at the moment," he said, "there's been a big swing from the Chardonnay set, who are all in favour of a republic, to the people of the younger generation who aren't."

Lisa Donahoe and Barbara Johnson had come from Canada. "I couldn't sit as patiently as she does," said Lisa. "It's not easy being a queen," said Pragas Maya Krishnan, a barrister whose mother had come over from Singapore in the hope of a glimpse. "She doesn't have a very free life. She's restricted every moment." Krishnan works, he told me, in immigration. So wasn't he bothered by the privilege the Queen represents? He looked surprised, and shrugged. "No," he said. "Funnily enough, I'm not."

No one seemed to be. Christa Emberton, attendance officer at a secondary school in Essex, said she liked the Queen's "loyalty and commitment to the country". Lee Bishop, manager of a pet shop in Thurrock, said he didn't care about the class system. "At this time," he said, gesturing towards the steps where men in plumed helmets and gold-embossed tabards were now assembling, "no one's different to each other. They get to wear smart clothes, and go in there, and good for them."

And when the Queen finally stepped out of her car, looking very smart in a nice pale mint hat and coat, but also a little lost without the husband she hoped would be there to celebrate with her, everyone cheered. We couldn't watch the service on giant screens because the Queen had decided she didn't want giant screens. I watched it on my laptop in Starbucks, overlooking the cathedral steps, and people gathered around to watch it with me. "I think," said Philippa Crowdar, a property developer from Essex, "she's very sincere". Certainly, when Rowan Williams praised her "utterly joyful service", and the Queen, knowing that the eyes of the world were fixed on her, scowled, she seemed to be.

The music, as far as I could tell from my shaky internet connection, was magnificent; the singing was magnificent; the setting was magnificent. It seemed, after the hotchpotch of the night before, an event to match the occasion, an event that reminded those of us who were watching that we are all part of history. It reminded us that, in the babble of voices that surrounds us, there is something to be said for silence, and that respect, in an age when people demand it, and young men die on the street for it, is something you build up over years. This may or may not have been a celebration of a constitutional system, and of traditions that involve trumpets and men in tights. But it was certainly a celebration of a woman who has more than done her time, and done it with dignity and grace.

"She looks really good, even though she's old," said eight-year-old Trinity, who climbed on her father's shoulders to catch a glimpse. But her friend Valerie wasn't thinking about the Queen's appearance. "I think," said the 11-year-old, speaking on behalf of the nation, "she has achieved quite a lot".