On my way home from work the other day I impulsively hopped off the bus outside the British Museum to go inside and admire some of my favourite treasures, the Benin Bronzes.

These, if you’ve not heard of them, are the fabulous sculptures and casts from the West African kingdom of Benin, (the historic kingdom of Benin is part of modern day Nigeria, and is not to be confused with the neighbouring Republic of Benin).

In 1897, the British burnt the city of Benin to the ground, destroying many treasures, and looting others. The best surviving "Bronzes”, actually made from brass, are a series of plaques that adorned the royal palace, depicting kings and their attendants, and visiting European traders. These are now beautifully displayed in the British Museum.

Needless to say, the manner in which these treasures were taken from Benin is today highly controversial. Nigerian governments have argued that the Benin Bronzes are to their people what the Parthenon Marbles (also in the British Museum) are to the Greeks national treasures looted by rapacious imperial Britain, which should now be returned home.

Most Nigerians, I believe, share these sentiments, (although there are many who privately concede that the Bronzes may not have fared so well in Nigeria’s poorly run and sadly underfunded museums). Nonetheless, it’s hard to imagine that the Bronzes will be going back to Nigeria anytime soon. And at least in the British Museum, where admission is free, a large and diverse audience comes to admire them every single day.

1897. Now, that date rings a bell. It was, of course, Queen Victoria’s Diamond Jubilee, the 60th anniversary of her accession to the throne, the celebrations for which we now see as a kind of high-water mark of the British Empire.

Soldiers, governors, princes and prime ministers from colonies all over the world took part in an enormous parade through London, just four months, as it happens, after the sacking of Benin. You can watch the parade on this very early piece of news footage.

This year, 2012, Britain will be celebrating another Diamond Jubilee, that of Queen Victoria’s great-great granddaughter, Queen Elizabeth II.

The nature of the celebrations, it’s safe to assume, will be very different in tone to those of 1897, even if many British people retain a deep (and to some, mystifying) affection for their royal family.

Nonetheless, the occasion of this second diamond jubilee will give many British commentators an irresistible opportunity to take stock of how much has changed since the first, 115 years ago.

Britain’s place in the world is greatly diminished, and the past one hundred years has been a story of imperial retreat and decline. This country, in the famous words of Dean Acheson, lost an empire, and has not yet found a role. Judging from this interesting article in the Guardian, the search for a post-imperial identity goes on today, as the anguished debate about Britain’s place in Europe drags on and on.

Something in Linda Colley’s piece took my eye that Brazil now has more embassies in Africa than Britain does. (I was so struck by this that I had to confirm it myself, using that font of all reliable knowledge, Wikipedia.

The tally, if you’re interested, is Brazil 34, the UK 33). What a telling sign of how our world is changing! Mind you, I've seen evidence of it myself. A couple of years ago I became friends with a Brazilian diplomat in Athens, who was being sent off to the West African state of Togo, to become his country’s first ambassador there. He had only a vague notion of where Togo was.

And I also remember travelling through Lesotho and Swaziland a few years ago, when Britain announced it was closing its embassies there. There was general astonishment and dismay in these two former British protectorates that London was turning its back on them. Once upon a time, Britain ruled from Cape to Cairo, striding over Africa, plundering whatever it wanted. Which brings us back to the British Museum, and the Benin Bronzes.

It would be foolish to say that much has not changed in Britain’s relationship with Africa since 1897.

It would be hard to imagine, today, a European army marching into an African city, burning it to the ground, and carting off all the treasures. But in that case, what are the Bronzes still doing in Britain? Theorists of neo-colonialism would no doubt argue that the Bronzes continued presence here shows how even a diminished power continues to enjoy the fruits of empire long after formal decolonization.

They might also argue that European companies (and Chinese ones, and, increasingly, Brazilian ones) continue to loot African resources. Perhaps that’s true, although the cynic inside me says that these days it is at least necessary to pay off a corrupt local elite before carrying off the treasure.

Much to think about, downstairs in the British Museum, whilst admiring the Benin Bronzes, in this jubilee year.