There are very few wild Siberian tigers left in China, perhaps fewer than 40, but there are conservation centres where the tigers are protected and breeding programmes have been successfully introduced. If it were not for these centres, the animals would be extinct, so people who talk rather too emotionally about ‘wild or not wild’ are missing the point. The tigers in these conservancies are not tame – they will eat a man in a heartbeat – but they are protected and looked after in their natural habitat. It is not a zoo but it is safe acreage for magnificent animals. Conversely, it is not safe acreage for humans and security is extremely tight.

In January this year, I travelled to Harbin in North East China, reputedly the coldest major city in the world in winter months. Indeed, when I arrived, the temperature was -35 degrees. The area has a tiger conservancy so sightings are guaranteed.

I hired a fixer and an interpreter, and we went, bearing gifts, to the breeding-centre manager in his office. I showed him my work with lions and elephants, and also my image that President Xi had received during Prince William’s state visit in the summer. I had no idea what the manager was saying but safety clearly came first in his mindset. It was clear there was no way I was getting out of a vehicle – he made a munching expression with his face and I got the gist. He agreed, however, to me sitting in a vehicle with removable windows and the biggest possible gap between the cage bars, big enough for my camera but not a tiger’s head. The interpreters also arranged for radio contact between my driver and the principal feeder of the tigers, who brings the tigers sheep, deer and chickens to eat, and throws them out of the back of his 4 x 4 in a hurried manner that hints of a few scary moments in the past.

The first day in the park was used for scouting. It was freezing but I needed to spend time finding a hill and then think about the hill versus the position of the cold winter sun, and where our bashed-up vehicle with my eight-inch gap could sit comfortably on an icy slope and capture a collective of tigers.

I watched the tigers around that hill on the first morning and I saw an opportunity, but I needed big depth of field, which removed the possibility of using any telephoto lenses. It was clear that I was going to have to be very close and looking uphill with a standard lens or an 85m. Then we just had to work with nature and be patient.

The second day was again a freezing -25 degrees, but that was exactly what I wanted. I needed a picture before 10am, as after that the winter sun is not kind enough for group portraits, so this meant working at the coldest part of the day. We had bought 25 chickens and the driver spoke constantly on his radio to the tiger feeder about what we were looking for. It was clear from their heated exchanges that this was a first for them. It was a partnership between me and four Chinese people: the driver, the feeder and his assistant and, most importantly, the interpreter.

The Siberians is a big moment in my journey. It is visceral and demands attention. As someone said to me soon after I took it, there is a deadly serenity to the image. I could not have expressed it better myself. Pleasingly, all the tigers are pin sharp, so I got my maths right. Indeed, it almost looks like the cover of an HBO boxset. As with The Sopranos, I hope they all become stars. They made a great picture for me that day in North East China.