IT has all the ingredients of a John le Carre novel. For decades there are allegations of terrible abuse during the Mau Mau rebellion; historians are baffled by missing documentation. A court case finally prompts the UK Foreign Office to discover hundreds of boxes of previously hidden papers stored in a house, Hanslope Park, north of London.

They reveal not just the brutality — which historians had already unearthed — but official recognition of the illegal violence and dogged determination to cover it up. The Foreign Office attributed the forgotten boxes to “an earlier misunderstanding about contents” and stated that there needed to be an “improvement in archive management”. In a superbly smooth statement, the Foreign Office commented that “it was the general practice for the colonial administrations to transfer to the UK ... selected documents held by the governor which were not appropriate to hand on to the successor government”. I’d cast Bill Nighy for that bit of the script.

But the Mau Mau boxes are only a small part of a hoard of 2,000 detailing the end of empire in 37 British colonies. Without skipping a beat, foreign minister William Hague announced that their release was “essential to upholding our moral authority as a nation”. An odd comment to make while a court case was revealing detailed and graphic descriptions of horrific violence perpetrated by the British on thousands of Kenyans. Hague even had the chutzpah to go on to declare that our willingness “to shine a light on our faults and to learn from mistakes of the past is an enduring strength of British democracy”.

So just to be clear: cover-ups are problems in “archive management”, records of illegal violence are “inappropriate”, and in case we are in any doubt, Britain’s moral authority as a nation continues, regardless of the inconvenient truth. For anyone interested in how narratives of national identity are maintained through all manner of contrary evidence, this is a textbook case.

Myths about the British empire abound, and one of the most cherished is that its end was orderly. As Peter Oborne put it recently, “compared with the French, the Belgians or the Italians, we handed over our colonial empires with good-natured and civilised ease”.

The reality — as historians have pointed out — was violent, often chaotic, and marked by a desperate struggle to maintain British prestige and influence. It is the end chapters of the empire that reveal most starkly the naked pursuit of self-interest. — The Guardian, London