There are times when everything comes together in a film. This was one of those times.

The Secret History of Our Streets was a big popular and critical hit for BBC 2. It was also great fun – and hugely satisfying – to make.

There was a brilliant idea at the heart of the series: profile six London streets through history until today, using the famous “poverty maps” of the Victorian philanthropist and reformer Charles Booth as a jumping off point.

These remarkably detailed maps were created by Booth with data gathered by visiting – literally – every street in London. The maps used colour coding to represent the level of poverty on each street. From black for “Lowest class. Vicious, semi criminal” to dark blue for ‘Very poor. Casual, chronic want’ to yellow for ‘Wealthy.”

I knew nothing about the life and history of The Cally – or the proud people who live there – when I first walked down that rather sad North London street on a windswept October day. It looked like any other scrappy, down at the heels, purely functional main road that you might pass through, but find no good reason whatsoever to remember.

Eight months later, I again walked down The Cally, on my way to watch the film go out on BBC 2 at a pub with a crowd of the road’s residents. Everything had changed for me. I knew every inch of that street and many of its people. Instead of a vague sense of place, populated by interchangeable figures, The Cally now evoked in me both affection and wonderment.

Affection for that underdog stretch of road and all the many residents who shared their thoughts, impressions and memories with me and the camera. (Then bought me pints.)

And wonderment at how beneath the seeming solidity and inevitability of the Caledonian Road – or any road – as we see it existing before our eyes in the present, there are shadows and ghosts everywhere, ways things were, might have been and might one day be, sneaky turns of history mostly lost in time.

To tell the story of how and why The Cally was always a kind of underdog road – and how that underdog spirit saved it from an ill thought out Kings Cross development scheme that would have destroyed it – I relied on the voices of “regular” people.

From the lovable Eileen, who grew up on the road and now ran its most popular local…

To her arch rival Andrew, the detested landlord who owned half the street and rented underground shoeboxes to party hardy young Australians who came and went …

To George, a posh Chelsea developer whose Victorian ancestor – and fellow developer – saw a bucolic field just outside booming Central London and decided to run a road through it…

To old Jim, who remembered when cattle used to run through the streets of the area on their way to the slaughterhouses of the great Caledonian Market. And how some old men used to hide in the shadows for pervy assignations with the doomed animals. (If you want to know the details and can stomach the awful truth, watch the film.)

There’s rarely enough time in television anymore to really dig deep and spend time learning about people and places. The BBC let everyone working on this great landmark social history series do that. The results were illuminating – and occasionally magical. I feel lucky to have been part of it.