It can't be easy being married to the Archbishop of Canterbury. Jane Williams, the present incumbent of that strange position, edited a book called Marriage, Mitres and Being Myself, which was a celebratory offering but which candidly set out the drawbacks: bureaucracy, no privacy, constant guests. It must have been harder still in the 1880s, especially if the archbishop in question was the frighteningly pious Edward Benson, and especially if the situation was further complicated by your being a lesbian. Rodney Bolt clearly has an eye for a good subject. He has written an utterly absorbing biography of a woman who is very much worth reading about, and who was herself a deeply intelligent reader of her own late-19th-century world.

Young Minnie Sidgewick, who loved nothing more than "the simultaneous enjoyment of a soft chair, a book and an orange", had no idea what she had coming. When she was 11, she made the mistake of reciting a passage from Tennyson about the glories of love, at which point her cousin Edward promptly decided to marry her. Edward led Mary down the aisle as soon as she was 18, marched her round the basilicas of Europe, and installed her at Wellington where, at the age of just 29, he was the newly appointed headmaster. The basic parameters of Mary's life were set out before she had had much chance to consider the options, but she was determined to make the best of it.

She had babies in quick succession and the children were competitively literary from the moment they learned to talk. Those who wanted bread at breakfast had to ask in rhyming couplets. Everyone was prolix by default, in ways that partly compensated for repressions elsewhere. The family magazine, to which each contributor had to submit at least four pages, must have been one of the lengthiest in lengthy Victorian England. Among the contributors was Fred, the future EF Benson, who wrote the Mapp and Lucia novels as well as more than 100 others. Mary would eventually have whole bookcases devoted to the publications of her offspring. No wonder her daughter Nellie came up with the kind of maxim necessary to survive in such a household: "Contradict, while you are thinking what to say."

Because Edward was so regularly promoted (from headmaster to bishop to Head of the Church), Mary had to keep moving the entourage of Bensons around the country, from Wellington to Lincoln to Truro to London. Arriving at Lambeth Palace, she looked round and despaired. The various houses and their contents are described with brio by a biographer who knows the power of an ottoman and a whatnot  not forgetting a sarcophagus in the garden. With each move the family collections grew: "the wheezy harmonium, the beds, books, and card games, the bronzed dessert dishes from the working men's bible class, the butterfly collections, mahogany cabinets, sumptuous sideboards". It's like the lists of objects that Virginia Woolf conjures in Orlando to summarise a whole Victorian way of life, though even Orlando (as far as we know) does not have the pleasure of owning a giant pincushion made for the queen. In one sad and evocative scene, a queue of enormous and superfluous wardrobes lines up outside the front door for admittance.

The houses were packed with Mary's admirers as well as wardrobes; streams of eminent guests adored her dazzling repartee and her quiet emotional tact. Gladstone thought her the cleverest woman in Europe; Tennyson, Browning, Henry James all came to sit on the ottoman. Edward, in the background, comes off badly. Bolt has little sympathy for the man who storms in to accuse Mary of neglecting the antimacassars. Mary herself tried much harder to love her husband, and one can't help but admire his mighty energies. But the real loves of Mary's life were women, and there were many of them.

She began by proudly numbering her "schwärmereien": by the age of 26 she was embarking on enchantment number 39. But things grew complicated. Mary's agonised diaries give moving evidence of the "impossible" task she faced in trying to reconcile her devout faith and her sense of duty to Edward with her overpowering love for the women who wanted a part in her life. Two of these women, while loving her passionately, made strenuous efforts to show her the sinfulness of this love. Mary learned the guilt they taught her and prayed painfully, repeatedly, that "all carnal affections may die in me". This artificial damming up took a physical toll, and there are passages here that are gruelling to read.

Not one to waste time dying, Edward collapsed during confession one morning, and was dead by the end of the service. Lightning struck Canterbury Cathedral just as his memorial was being unveiled. Then all fell quiet, and Mary was left to start again. Bolt's preface sets us up to expect a great release and a feisty demonstration that life begins at 55. What we get, as Mary builds her life with Lucy Tait and struggles to understand her troubled grown-up children, is more melancholy, and much more engrossing.

This biography is partly structured as a "commonplace book" allowing threads of association to be woven back and forth. "On the banks of the stream of the main narrative" Bolt has placed quotations from contemporary poetry, apposite diary entries, postcards, bits of Benson family fiction. So when Mary fails in domesticity we get a selection of "Ideal Wives", and as she falls desperately in love we get a series of "Innocent Intimacies". It is an evasive technique allowing comparisons to go unarticulated. But well judged evasions can be eloquent. And when the book is closed there are images that keep on talking. A disturbed daughter walks home to the mother she hates; spiky flowers look menacingly from a flowerbed named the Apostolic Succession; Mary Benson and Ethel Smyth argue vehemently about women's suffrage in a rotating summerhouse one afternoon a century ago. It's a rich weave, and it's devilishly good.

Alexandra Harris's Romantic Moderns is published by Thames & Hudson.

It can't be easy being married to the Archbishop of Canterbury. Jane Williams, the present incumbent of that strange position, edited a book called Marriage, Mitres and Being Myself, which was a celebratory offering but which candidly set out the drawbacks: bureaucracy, no privacy, constant guests. It must have been harder still in the 1880s, especially if the archbishop in question was the frighteningly pious Edward Benson, and especially if the situation was further complicated by your being a lesbian. Rodney Bolt clearly has an eye for a good subject. He has written an utterly absorbing biography of a woman who is very much worth reading about, and who was herself a deeply intelligent reader of her own late-19th-century world.

Young Minnie Sidgewick, who loved nothing more than "the simultaneous enjoyment of a soft chair, a book and an orange", had no idea what she had coming. When she was 11, she made the mistake of reciting a passage from Tennyson about the glories of love, at which point her cousin Edward promptly decided to marry her. Edward led Mary down the aisle as soon as she was 18, marched her round the basilicas of Europe, and installed her at Wellington where, at the age of just 29, he was the newly appointed headmaster. The basic parameters of Mary's life were set out before she had had much chance to consider the options, but she was determined to make the best of it.

She had babies in quick succession and the children were competitively literary from the moment they learned to talk. Those who wanted bread at breakfast had to ask in rhyming couplets. Everyone was prolix by default, in ways that partly compensated for repressions elsewhere. The family magazine, to which each contributor had to submit at least four pages, must have been one of the lengthiest in lengthy Victorian England. Among the contributors was Fred, the future EF Benson, who wrote the Mapp and Lucia novels as well as more than 100 others. Mary would eventually have whole bookcases devoted to the publications of her offspring. No wonder her daughter Nellie came up with the kind of maxim necessary to survive in such a household: "Contradict, while you are thinking what to say."

Because Edward was so regularly promoted (from headmaster to bishop to Head of the Church), Mary had to keep moving the entourage of Bensons around the country, from Wellington to Lincoln to Truro to London. Arriving at Lambeth Palace, she looked round and despaired. The various houses and their contents are described with brio by a biographer who knows the power of an ottoman and a whatnot  not forgetting a sarcophagus in the garden. With each move the family collections grew: "the wheezy harmonium, the beds, books, and card games, the bronzed dessert dishes from the working men's bible class, the butterfly collections, mahogany cabinets, sumptuous sideboards". It's like the lists of objects that Virginia Woolf conjures in Orlando to summarise a whole Victorian way of life, though even Orlando (as far as we know) does not have the pleasure of owning a giant pincushion made for the queen. In one sad and evocative scene, a queue of enormous and superfluous wardrobes lines up outside the front door for admittance.

The houses were packed with Mary's admirers as well as wardrobes; streams of eminent guests adored her dazzling repartee and her quiet emotional tact. Gladstone thought her the cleverest woman in Europe; Tennyson, Browning, Henry James all came to sit on the ottoman. Edward, in the background, comes off badly. Bolt has little sympathy for the man who storms in to accuse Mary of neglecting the antimacassars. Mary herself tried much harder to love her husband, and one can't help but admire his mighty energies. But the real loves of Mary's life were women, and there were many of them.

She began by proudly numbering her "schwärmereien": by the age of 26 she was embarking on enchantment number 39. But things grew complicated. Mary's agonised diaries give moving evidence of the "impossible" task she faced in trying to reconcile her devout faith and her sense of duty to Edward with her overpowering love for the women who wanted a part in her life. Two of these women, while loving her passionately, made strenuous efforts to show her the sinfulness of this love. Mary learned the guilt they taught her and prayed painfully, repeatedly, that "all carnal affections may die in me". This artificial damming up took a physical toll, and there are passages here that are gruelling to read.

Not one to waste time dying, Edward collapsed during confession one morning, and was dead by the end of the service. Lightning struck Canterbury Cathedral just as his memorial was being unveiled. Then all fell quiet, and Mary was left to start again. Bolt's preface sets us up to expect a great release and a feisty demonstration that life begins at 55. What we get, as Mary builds her life with Lucy Tait and struggles to understand her troubled grown-up children, is more melancholy, and much more engrossing.

This biography is partly structured as a "commonplace book" allowing threads of association to be woven back and forth. "On the banks of the stream of the main narrative" Bolt has placed quotations from contemporary poetry, apposite diary entries, postcards, bits of Benson family fiction. So when Mary fails in domesticity we get a selection of "Ideal Wives", and as she falls desperately in love we get a series of "Innocent Intimacies". It is an evasive technique allowing comparisons to go unarticulated. But well judged evasions can be eloquent. And when the book is closed there are images that keep on talking. A disturbed daughter walks home to the mother she hates; spiky flowers look menacingly from a flowerbed named the Apostolic Succession; Mary Benson and Ethel Smyth argue vehemently about women's suffrage in a rotating summerhouse one afternoon a century ago. It's a rich weave, and it's devilishly good.

Alexandra Harris's Romantic Moderns is published by Thames & Hudson.