This is the time of year when my thoughts turn to Cawnpore and the events of 1857.

Although the British had been establishing themselves in India for some time before 1757, the battle of Plassey is often seen as a turning point, marking the beginning of British rule in the country. This was certainly a view shared by many Indians and the idea had grown up among some but British rule would last for 100 years, ending in the summer of 1857.

In the early years of British rule, colonial officers were surprisingly well assimilated into Indian society. Many took Indian wives. In some cases these were little more than mistresses, but a lot of officers formed Indian households and raised children in the country. There was genuine interest in the local customs and religions, which were generally respected. Many parts of India were ruled by people who were not originally from that area and the change from an Indian overlord who had conquered their region to a European one meant little to the locals. Over time, though, the nature of British rule changed. European women travelled out to India in search of potential husbands and the custom of taking native wives was frowned upon. The Church saw India as fertile ground for new converts and preachers arrive who denounced local customs and religions. The country was flooded with new officials who saw a job in India as a way to make a fortune and who were little interested in the culture of the country, often despising the natives and their beliefs.

By the mid-19th century, many Indians were fractious and resentful of the British. Yet at the same time the British were so confident of their apparently inalienable right to rule that the majority of the soldiers employed to maintain British power in the sub-continent were, in fact, Indians. Furthermore, Indian troops were seeing a reduction in the respect and privileges that used to be accorded to them in the earlier years of British rule.

Throughout the spring of 1857 there were indications of growing Indian discontent and calls for revolt, yet when the first Europeans were killed by mutinying Indian soldiers – in Meerut on 10 May 1857 – it seems to have taken the authorities by surprise.

Once the mutiny had started it spread rapidly from regiment to regiment. The revolt spread to the civil population too, taking on the character of a general uprising, though some Indians never turned against the British and those who did were riven by factional in-fighting.

Soon much of north-west India was rising against the British, but many of the Europeans stationed in India struggled to believe that it was really happening. Officers often implored their troops to stay loyal. Some troops did, others shot their commanders down. In Cawnpore (now Kanpur), a town about 250 miles from Meerut the local British commander, General Wheeler, did not expect any trouble even after news of the Mutiny reached the town. His military force was negligible and the local ruler was thought to be sympathetic to the British.

In the event, Wheeler (himself married to an Indian) proved horribly mistaken. The siege of the British at Cawnpore and the massacre that ended it was one of the darkest single incidents of 1857.

This is the background to the second of the John Williamson stories, Cawnpore. Cawnpore is set during a particularly vicious war, but it is not a war story. The book centres on John Williamson, the narrator of The White Rajah. (The story stands alone and you don’t need to read The White Rajah first.) His life in the Far East has left him more comfortable with the princelings of the local Indian court than with the class-ridden Europeans he works with. He has friends on both sides of the conflict and struggles to stay true to them all. In the midst of a war that is fought with terrible ruthlessness, he tries to remain a decent person.

Cawnpore is a story about idealism and reality; about belonging and exclusion. It looks at the British colonial project and how it went so horribly wrong. It makes most people cry.

At the time that I wrote it, my son was serving in Afghanistan, in a conflict that can trace its origins back to the 1850s and before. Yet again, British troops were fighting and dying for a way of life they didn’t understand. Researching Cawnpore made me realise that the important thing about the war in Afghanistan wasn’t that it was right or that it was wrong: it was that it was futile.

Cawnpore is my favourite of all the books I’ve written. I do hope you read it.