According to Andrew O'Hagan, this is "the most brilliant British memoir published in years". He is right on one count: Mother Country is brilliant. But is it a memoir? Not exactly. Mother Country is a slippery book - much of it is set on water, in dwellings that seem to be besieged by a rising River Thames. It is both a detective story and a social history, and it tells of Harding's search (he was adopted at birth) for his natural mother, Margaret Walsh. She, according to Harding's adoptive mother Maureen, was a "poor but kind" Irish woman who worked at Woolworth's.
Harding may intend to find out about Margaret, but what he ends up discovering is that it is Maureen - the mother he thought he knew - who has lived a surprising life. If Harding's story is partly a "class fable" (born on a White City housing estate, he was transported to a smart house in Airlie Gardens), it turns out that his is not the only one. Harding writes very well about class, avoiding caricature and deftly conveying the snobbery and foibles of those born into privilege. His grandmother, Mim, is often found with a hot-water bottle tucked about her person, and has wild ducks in her bedroom. Aunt Rosemary may have been a favourite relative, but she is also a brute. "My little relatives are splendid," she says as she looks out at Harding's own children, playing in a pub garden, before she delivers, casually and with exquisite cruelty, a blow to her nephew that is breathtaking in its heartlessness.
Harding absorbs her punch as he absorbs all information - and most of it is disappointing - with unselfconscious stoicism. "It didn't do to let things slip past," he writes at one point, musing on the significance of Eliza Doolittle being Maureen's heroine (Nancy from Lionel Bart's Oliver! is another), "even if you weren't sure what purpose they served."
Harding is in his late forties when he begins his search. His father, Colin, a man who was good at bridge and drink-ing, complicated and belittling (no wonder Harding learned the art of escape), is already dead. Maureen, his mother, ravaged by drink and Alzheimer's, dies halfway through, as does Aunt Rosemary, his half-sister Jill and his godfather of sorts, a monster called Boris. (The book is full of monsters: the serial killer Reginald Christie and Lord Lucan are hovering presences; this is a story in which mothers are not the only ones to disappear.) Harding grasps at possible parents - a Walsh in Wembley, a Webb in Morden - only to discover that they are, in fact, what they seem: utter strangers.
Harding's reliability is one of the few things the reader grasps about him as a grown-up. His personal history - childhood with Colin and Maureen between Notting Hill and the Thames, boarding school, studying something or other at what Maureen calls "Varisty", escaping one summer to stay with Aunt Rosemary - is not what he dwells on. He shines a light on to certain episodes from his past only insofar as they might illuminate what he is really after: the stories of Maureen, and Margaret, and also of White City, and a corner of Ladbroke Grove. (Apart from everything else, Mother Country is a fascinating portrait of west London in the 1950s.) Harding gives as much space, for example, to a description of a February sky as he does to the loss of his innocence as a small boy. "It's true that when Colin and Maureen sent me to boarding school, at the age of seven, a kind of screen came down between us. Indeed, we lost each other at that point and none of us really found a way back."
The effect of this ruthless refusal to indulge or even describe feeling is dazzling. Mother Country deals in revelation, and Harding doesn't shy away from making big statements or writing down big thoughts. It's just that he doesn't go in for self-examination, an omission both disconcerting and admirable in a book about finding one's roots. Mother Country may be about two mothers in particular, but it reveals much about mothers in general - and, as the title suggests, the complicated territory they inhabit in our lives.
There are moments when Harding gets stuck in town halls with electoral registrars and records of births, deaths and marriages. These are trying, but do not last long. Just as Harding begins to get bogged down in too much detail about too many Walshes, the right one appears, as if by magic. The meeting between Harding and Margaret is touching and vivid. The passage that follows, describing poor, mad, ultimately heroic Maureen, is a remarkable piece of writing - proof that prose can be properly powerful and restorative. I read it again and again, and each time, like the rest of Mother Country, it blew my heart wide open.
Daisy Garnett is a contributing editor of Vogue