It was a very British kind of celebration.
The couple were married in Westminster Abbey in 1947
As the drizzle came down on the grey London pavement, Westminster Abbey witnessed a distinctly restrained display of pageantry.
This was, after all, the diamond wedding anniversary of the head of state and her consort.
Elsewhere, such an event would probably be marked with fireworks, triumphal music and military parades.
Here, the Queen and the Duke of Edinburgh opened a new public walkway and unveiled a plaque.
There were no street parties, no state banquet. The night before, Prince Charles hosted a black tie dinner for his parents and 20 close friends. And after the church service, that was it.
But this was a couple whose marriage of 60 years had been sealed in a very different age. A time of rationing, bomb-scarred cities, and making the best of one's circumstances.
With this backdrop cementing their union, you wondered what the royal couple made of the tight police security around Westminster Abbey, these defences against a less tangible threat than the one they faced in wartime.
As their car pulled through the light rain past the cordon, a crowd of perhaps 200 or 300 greeted them across the road.
Retired teacher Gordon Grove, 69, cheered as loud as any of them. A Union Jack hat shielding him from the weather, he had risen at 0630 to get here from his home in Evesham, Worcestershire.
"It's just fantastic, really, for any couple to stay together for 60 years," he smiled.
"My wife passed on this summer, and we'd been married for 43 [years]. I'm a great fan of both the Queen and the Duke and I felt I just had to show my appreciation."
Inside the Abbey, the mood was no less restrained.
The morning's one glimmer of showbiz was Dame Judi Dench reading a poem by poet laureate Andrew Motion, but its theme was marked by as much reserve as the rest of the occasion.
"Love found a voice and spoke two names aloud," Dame Judi read, "two private names, though breezed through public air / and joined them in a life where duty spoke."
Celebration of affection
Outside, pushed against the railings, royal fan Jean Harrison, 63, expressed similar sentiments in plainer language.
The Queen is the first UK monarch to reach a diamond wedding anniversary
"They've done ever so well, haven't they," she said.
"She's not had the easiest time of it, but she's come through OK in the end.
"And Philip might be a rogue, but he's a loveable rogue."
Much of the crowd was made up of foreign visitors to London, unable to believe their luck that they were setting their eyes on a real-life British monarch.
"When I go home, I expect everyone will ask if I saw the Queen," laughs 21-year-old Besa Cowen, from Melbourne, Australia. "But I really did.
"Events like this make you realise how much tradition there is in this country."
And the weight of history was surely on the minds of both the Queen and Prince Philip as they made their way out of the service.
They had experienced a day very much in keeping with their partnership, after all. A contained, unshowy celebration of affection, and one clearly forged in a different age.
Without fanfare, the celebrations were over. A burst of sunlight had already begun to shine through the drizzle.