Theresa May: The shy, studious child who became Britain's loneliest Prime Minister

The first time Theresa May entered the classroom of her new school she had to be carried through the door kicking and screaming.

"What a silly little girl," the headmistress told 5-year-old Theresa.

She never forgot the insult.

And so began a school career that could be said to have been a foretaste of what lay ahead when she entered the House of Commons.

She would achieve dizzying success - places at grammar school and then at Oxford, a seat at the Cabinet table and ultimately the keys to No 10 - but endure repeated humiliations and never really win the affection of either those in authority or her peers.

The rather solitary little girl, an only child more comfortable talking to her elders than friends her own age, grew to be a lonely Prime Minister.

Her husband and a tiny handful of advisers replaced the usual giant entourage of ministers, aides and companions premiers rely upon to sustain them.

It is only by digging back deep into her early years that we can fully understand quite why she clung on for so long, in the face of so much hostility.

It is a story that helps explain many of the choices she made as Prime Minister - decisions that, on the surface at least, seemed inexplicable and continue to shape Britain's post-Brexit future.

It is often said of May that she relies too closely on a tiny inner circle, and lacks the capacity to either compromise or acknowledge voices outside her minuscule circle of trust.

Recently that inner circle shrank to just one: her husband, Philip, giving May's latter days at Downing Street a siege-like atmosphere, where she was the last to appreciate her days in the bunker were drawing to a close.

The foundations for this blinkered mindset lie in the vicarage where she grew up in rural Oxfordshire in the Sixties and early Seventies.

May's father, Hubert Brasier, an Anglo-Catholic vicar so "high" he contemplated becoming a monk, and her mother, Zaidee, came late to parenthood. The home they raised young Theresa in was quiet and ordered.

With no siblings, she enjoyed cooking with her mother and discussing cricket and current affairs with her father.

At the age of 12, and arising directly from those conversations with Hubert, she began the relationship that has meant more to her than any bar that with her parents and husband: a love affair with the Conservative Party.

Without the usual distractions of teenage years, she joined the party and Saturdays were spent stuffing leaflets into envelopes at the local Tory HQ.

May's fellow pupils at Wheatley Park School remember her as quiet and studious.

She took part in the school's mock general election of February 1974 - but lost to the girl supporting Labour.

One of her teachers remembers her delivering a compelling speech, easily the best of the candidates, but she lacked the friendships and charm necessary to woo the waverers.

It was at Oxford, where she studied geography at the all-female college St Hugh's, that May came across more like-minded souls, and for once found herself at the centre of something approaching a social whirl.

Her circle included Alicia Collinson and Alicia's boyfriend Damian Green, who May would later appoint to her Cabinet, as well as another future Tory MP, Alan Duncan.

It was her most glamorous friend, Benazir Bhutto, the future prime minister of Pakistan, who in her final year introduced her to Philip, while all three were at a disco organised by the university's Conservative Association; they clicked instantly.

Philip was 19, a year younger than May (who was so bright she had skipped a year at school) and had only just arrived at Oxford, where he was studying history.

He had already caused a stir by winning a freshman's debating competition, and would go on to serve as president of the Oxford Union. Understandable, then, that friends assumed it would be the talkative Philip who would enjoy a stellar political career, rather than the shy Theresa.

The inner circle expanded. Living in Wimbledon, they both began careers in banking and held ambitions for public service: she was elected to Merton Council and he worked his way up to become chairman of the local party.

Tragically, within a year of the Mays' marriage in 1981, her father was killed in a car crash and a few months later her mother Zaidee died of the multiple sclerosis that had begun to affect her when May was still a schoolgirl.

The events were so shattering that May could not bring herself to tell her friends, many of whom did not find out until some years later.

As she later recalled, Philip's was the only support she needed: "He was a real rock for me", she once said. "He has been, all the time we've been married, but particularly then, being faced with the loss of both parents within a relatively short space of time."

The grieving couple had hoped at that point to go on to have a family. She and Philip both became godparents to the children of his brother, David. The early death of her god-daughter last summer from cancer led to her announcement of a new government cancer strategy in October.

But the children the Mays dreamed of for themselves never came.

Believing it was more important to get on with their lives than to "dwell" on what might have been, it wasn't something they talked openly about.

As she later said: "Of course, we were both affected by it. Sometimes things you wish had happened don't, or there are things you wish you'd been able to do, but can't. I'm a great believer that you just get on with things."

But with busy careers and just each other, Mrs May and Philip turned further inwards, drawing away from even the close friendships they had formed at university, pouring their time, energy and emotional investment into the Conservative Party.

When May entered Parliament in 1997 the couple must have felt all the hard work had been worth it. But it took her 13 more years to reach a top post, under Prime Minister David Cameron, when she became Home Secretary upon the formation of the Coalition Government in 2010.

Even then, she rankled at being left outside Cameron's inner circle, formed of George Osborne and their closest advisers, all of whom were male and at least 10 years younger than her.

At night, while she was waiting to vote, the Mays would dine together in one of Parliament's restaurants. She was not seen in the bars and rarely stopped by a colleague's office to chat.

She appeared to acknowledge this as a failing when she addressed fellow MPs at the 1922 Committee last week, saying: "I don't tour the bars and engage in the gossip".

As a lesson finally learnt, it came 20 years too late. Through a variety of roles in opposition and in power, May never learned the knack of listening to other people's ideas or accepting alternative viewpoints. It was her and Philip against the world, and that was enough.

Baroness Jenkin, who got to know May when they co-founded an organisation to encourage more women to become Tory MPs, was happy to be invited to her 50th birthday party in 2006, but was somewhat surprised at the guest list.

There were few friends from either school or university; instead May had invited a number of constituents from Maidenhead to help celebrate her milestone, including the local butcher.

Finally achieving the top job at the age of 59, after so many years in politics, must have felt like a huge affirmation. She enjoyed the prestige of it, the respect, the honour.

However tough it got, for all the insults and abuse, there was never any question that she would stand aside before she was actually forced to.

It is often said that being a prime minister is a lonely job.

For a woman like May, who craves respect rather than love or affection, it must have felt like the perfect fit for a while.

Her self-reliance, honed from her life experiences, had brought her an immunity from needing close friends and may have given the impression of inner steel - but it masked a stubborn core.

She failed to see she lacked the skills of persuasion and compromise necessary to be a truly successful prime minister, particularly given the impossible task of Brexit.

And by the end, there was no one left to tell her otherwise.

- Rosa Prince is the author of Theresa May: the Enigmatic Prime Minister