There’s always a beginning. The University of Rome is cold stone and silence, the students long gone home, the halls in shadows. In the whole dark night there is only one flickering light: the window of the anatomy building. Inside, alone in a room full of cadavers, Italy’s first female medical student is standing over the opened chests of the dead, smoking. The end of her cigarette flashes red.

Maria Montessori was born in 1870, the first year of the new Italian nation, at a time when the military and modern public education walked shoulder to shoulder, boot to boot. The tools of industrialisation were applied to the classrooms of her youth: schools were places of isolation and fear, towering desks and repetitive tasks.

Endless drills, rote learning, curricula and circulars were made to bludgeon the new Italian citizen into shape, but over half the population remained illiterate. As an adult, Montessori would describe the children in those classrooms as ‘butterflies mounted on pins… fastened each to his place, the desk, spreading the useless wings of barren and meaningless knowledge which they have acquired.’

Maria’s father Alessandro disapproved of his only child’s academic enthusiasm. It was wrong, in a girl, in a woman. Maria herself couldn’t explain why she chose to chase medicine. Only that her science was mixed with signs; that she interpreted the information the world presented her with in a different way to other people. Later, one of the women who would flock to her side and spend their lives in the service of her ideas described Maria’s decision as ‘happening all in a moment.’

‘She was walking in a street when she passed a woman with a baby holding a long, narrow, red strip of paper. I have heard Dr Montessori describe this little street scene and the decision that then came to her. At such times there was in her eyes a long deep look, as if she were searching out things which were far beyond words. Then she would say, ‘Why?’ and with a little expressive movement of her hand indicate that there are strange things happening within us guiding us towards an end we do not know.’

When Maria applied to the University of Rome’s Medical School, she was told that her application was absurd. Grotesque, the idea that a woman should study the human body. Her nature would never be able to handle it.

Maria went on to study maths, science and physics. In the corridors of the University of Rome, when the men whistled at her, she arched an eyebrow over her perfectly feminine frocks and told them: ‘the harder you blow, the higher I’ll go.’

Holding her perfect grades in her fist, she managed to bully and cajole her way into the Medical School in 1893. The rumours about her ran wild in the press. Journalists muttered that it was the Pope who intervened on her behalf. Other people said: don’t be ridiculous. It will never last. She can’t.

She performed her anatomy studies late at night, when there were no male students to be scandalised by her presence. Walking home through the deserted streets she spat bile into the frozen gutters, her heart thumping, her head spinning. Beset by terrors, knowing that she was alone.

Maria graduated from medical school at the head of her class, with early clinical experience in psychiatry and paediatrics and the prestigious Rolli prize under her belt. The lady doctor, the first one. There’s always a beginning.

She was drawn to ‘phrenasthenic’ children, a hold-all category that described a litany of misunderstood conditions, illnesses, disabilities and deprivations. Children who were different; children who were told they couldn’t. In 1897 she joined a research program in the university’s psychiatric clinic.

In the squalid Roman asylums, in search of patients to study, Montessori watched as children scrabbled on the floor with crusts left over from their meals, and saw the anger on the faces of their caretakers who snatched the mess away.

They’re disgusting, said the caretakers. No, thought Maria. They’re bored. They’re desperate. Their minds are dying. Trapped, pinned.

At 28, she set up the Orthophrenic School with Dr Giuseppe Montesano, embracing a broad spectrum of socially and physically disadvantaged children. She replaced their crusts of bread with what she called ‘didactic’ sensory teaching materials, that she then refined, over and over: sets of shining beads, a flash of red cloth to be buttoned, laces tied, colours and shapes and feels. The children must learn to educate themselves. Like she had.

It worked. In examinations, after only a short time, the children of the Orthophrenic school did better than the ‘normal’ children, the tortured butterflies of the industrial classrooms.

And in secret, during those first wildly successful years, while in public she graced newspapers and spoke at conferences and received awards and spoke on behalf of the child, Maria had a child of her own.

She never talked about her love affair Dr Giuseppe Montesano. Giuseppe couldn’t, or wouldn’t, marry her. And for the first and last time in her life, Maria gave in to outside pressure. When her son Mario was born, he was immediately sent away. There was only so far, the families felt, that you could push. An illegitimate child would have ruined her, the now-famous lady doctor.

Later in life, Mario would recall the woman in black, an aunt, who would come and stand on the edge of his games every few months, rarely talking, always at a distance. When he looked up again, she would be gone.

All day, every day, Maria watched children, while her son grew up without her in the countryside. In 1901, Giuseppe Montesano married someone else. And Maria left the Orthophrenic School, at the height of its fame.

She threw herself into what she called ‘the education of herself’: went back to university and studied pedagogy and philosophy.

In 1906, to the horror of the University that claimed she was lowering the reputation of the medical profession, Maria opened the first Casa dei Bambini, ‘Children’s House’, deep in the Roman slums. Everything in the Children’s House was informed by Maria’s careful observation and development of materials that would unfold children’s minds: the furniture was a size that children could move and store, wash-stands and blackboards were scaled to their height, the room strewn with the ‘didactic materials’ that they could manipulate and arrange. The children were their own masters. And the results were unparalleled. They exploded into life.

‘We often believe ourselves to be independent simply because no one commands us, and because we command others,’ Maria said. ‘But the nobleman who needs to call a servant to his aid is really a dependent through his own inferiority. The paralytic who cannot take off his boots because of a pathological fact, and the prince who dare not take them off because of a social fact, are in reality reduced to the same condition.’

From Italy, Maria’s ideas launched across the ocean to America, bounced back to England and Spain, Holland and beyond. A tight network of women worshipers sprang up around her, nuns of her own special order. She toured constantly, published The Montessori Method in 1912, and trained teachers in her exacting methods: the careful production of the Children’s Houses and the results they could achieve. But even as the Montessori Method was beginning to take hold, the seeds of its dissolution were being laid.

Part of the problem was that Maria couldn’t allow the adults in her world the same freedoms, the same creative control, that she gifted her children. Adults had to stand back. Had to stay at a distance. To recognize their emotional power was to fear her own, and what its absence might mean for her child.

‘Every Montessori school is a scientific laboratory in which the teacher prepares the conditions of the experiment, and permits the phenomena to take place,’ Maria insisted when teachers tried to experiment with her ideas. Science, not emotion, raised children. Changes to the method, to the materials, could not be tolerated. In every country, vicious splits emerged between the Montessori ‘approved’ organisations and those who took matters into their own hands.

In 1913, when her own mother died, Maria finally allowed herself to approach her boy, who was no longer a child. Mario was fifteen years old. When Maria stopped her car outside his boarding school, he approached the ‘beautiful woman’ who had so often watched his life from afar. ‘I know you are my mother,’ he told her, and got in the car next to her. He would travel with Maria for the rest of her life, posing as her ‘nephew’, working on her method, defending her ideas.

Maria and Mario rode on the winds of catastrophe as war struck nation after nation across Europe. In 1922, a young Mussolini took up the Montessori cause. Over the next decade, he institutionalised the Montessori method in Italian schools. But when he began to insist that the children in her schools wear the fascist uniform, every Montessori school in Italy closed down overnight.

In 1939, 69 years old, Maria and Mario travelled to India to give a three-month training course at the behest of the Theosophical Society. They stayed for seven years. Another war had arrived in Europe. There would always be another war, Maria thought, always a bad ending, until we get the beginning right. Until we start in the right way.

‘The adult must understand the meaning of the moral defence of humanity, not the armed defence of nations. He must realise that the child will be the creator of the new world peace. In a suitable environment the child reveals unsuspected social characteristics. The qualities he shows will be the salvation of the world, showing us all the road to peace. And the new child has been born! He will tell us what is needed.’ What she wanted was a new world, ‘with new form and new fabric – not today’s harlequin mixture of rags and silk.’

Maria died in 1952, with Mario at her side. In her will, she finally acknowledged him as her son.

There’s always a beginning, so many of them it can be hard to see where things start. Today, Maria Montessori can be found in a million classrooms, in the coloured shapes and building blocks, in the dragging noise that children make as they take their own chairs across the floor, in every place that a child sits at his own height, and learns for herself.