Queen Elizabeth II: If the crown fits

At the age of almost 80 she is still the undisputed head of the clan. She is totally confident in her role as monarch and knows exactly what is expected of her and of her relatives. She also hopes, if not demands, that her family do what is required of them.

She can be intimidating, but with friends and family she is engaging company. Her tastes are simple and those who know her well say she is two different people - Lilibet (her pet name) and Her Majesty the Queen. Lilibet would far rather wear a headscarf than a tiara and would rather have a country picnic than attend a state banquet. As the Queen she rarely gets angry or lets her feelings show. The art of being royal, as she points out, is a matter of practice. "Training is the answer to a great many things," she says. "You can do a lot if you are properly trained - and I hope I have been."

Separated by her heritage from the rest of the world, we can only look at what we are allowed to see. People love her for her self-control and, paradoxically, for her inability to pretend. We love the way she enjoys herself when she is at a race meeting or with her family. She also has the ability - only indifferently achieved by lesser beings, to sit still. She doesn't move an inch and, even on her birthday on Friday, she will be working - "doing her duty", as she calls it.

This is something she has done since the age of 17, when she performed her first official solo engagement. The then princess was living at home, still being made to dress in clothes the same cut and colour as her 13-year-old sister, Margaret Rose. She was also painfully timid. As her father's equerry, Group Captain Peter Townsend, observed: "She was shy, occasionally to the point of gaucheness."

She did what was expected of her, however, and, having been made honorary colonel of the Grenadier Guards, she was driven to Salisbury Plain to perform her first grown-up inspection of the battalion.

As they neared Salisbury, the princess's face started to blanch as her nerves got the better of her. She was on the verge of being sick when Lady Della Peel, one of her mother's ladies in waiting, fished into her handbag and produced a barley-sugar sweet. "Munch this slowly," she commanded. "You will find it good for the stomach muscles."

It worked, and the princess managed to walk up and down the lines of soldiers as if she had been doing it all her life. And as the whole battalion marched past twice, she stood stock-still, handbag at her side. Her grandmother Queen Mary's instructions never to fidget had paid off.

At the age of 80 she will still be inspecting battalions of soldiers, only now those soldiers include her grandsons Princes William and Harry, of whom she is very proud. She has been criticised for being a distant mother, but her role as monarch allowed her little choice. As a grandmother, however, she can indulge her grandchildren.

The Queen prides herself on her memory and can recall dates and events precisely. If she is unsure she can refer to her diary, which she keeps locked in her desk. Several years ago she talked to a group of American students about her diary keeping: "My husband reads in bed and so does Prince Charles," she told them. "But I write a diary. It is far more truthful than anything you'll ever read in the newspapers."

Despite half a century of the rifts, rumours and broken marriages that have surrounded her family, the Queen has, according to Prince Philip, "the quality of tolerance in abundance". Her friend Margaret Rhodes explained: "She has this wonderful ability to shut off worries, putting them into one compartment and closing the door, so even if something pretty awful is happening ... she remains resilient, able to laugh and do her ordinary stuff."

For someone as reserved as the Queen, talking about her fears and showing weakness does not come easily. During her reign she has weathered many crises. In July 1982, a 31-year-old schizophrenic, Michael Fagan, broke into the Palace and made his way into the Queen's bedroom. In the accounts that followed the Queen was credited with acting calmly. As Mrs Rhodes remarked, "She has met so many dotty people that one more made no difference. Mind you, I think she was making light of it." Mrs Rhodes was right. The insouciance was feigned: the Queen had actually been profoundly unnerved by this violation of her privacy.

A week after the Fagan break-in the Queen went to hospital to have a wisdom tooth removed and then, a fortnight later, on 20 July, an IRA bomb exploded in Hyde Park, murdering 11 soldiers of her Household Cavalry, injuring 50, and killing seven horses.

The "corridor" policeman, who keeps an all-night vigil outside the Queen's bedroom, recalled that he heard the Queen sobbing and saying over and over, "the poor horses, my poor soldiers".

Ten years later, in what the Queen called her "annus horribilis", came the separation of the Prince and Princess of Wales, the divorce and remarriage of her daughter, Princess Anne, and the separation of Prince Andrew from his wife, Sarah, or "Fergie". If that was not enough, on her 45th wedding anniversary, while Prince Philip was in Argentina, Windsor Castle was engulfed by flames.

The Queen does not like many of the changes that have been forced upon her. She is constitutionally required to remain above politics, but it is no secret that she is apprehensive about much of what is being done by a Labour government, which still, in theory, acts in her name.

She disapproved of the removal of the 700-year-old right of hereditary peers to sit in the House of Lords, seeing it as a move against the hereditary principle which would eventually lead to the palace gates. On a more personal level, she detested a new, jazzed-up version of the National Anthem played during millennium celebrations - "my song", as she once quipped to Prince Philip.

In her final Christmas address of the last millennium, the Queen stressed "the importance of history" when she said: "The sheer rate of change seems to be sweeping away so much that is familiar and comforting... We can make sense of the future if we understand the lessons of the past. Winston Churchill once said that 'the further backwards you look, the further forward you can see'."

The Queen has plenty to look back on. But some things never change. She starts her day with a cup of tea. On the morning of her birthday it will be no different. The "morning tray" as it is called, complete with a silver teapot, water jug and milk, plus a plate of biscuits - which are given to the dogs - and a linen napkin bearing the royal cipher EIIR, is taken into her bedroom at 7.30.

The Queen's day then begins and, like every other day, she will be working, doing her duty. It is possible that, deep in her heart, she would like nothing better than to hand over to Prince Charles and retire. But that is not an option.

In 1947, when Princess Elizabeth came of age, in a broadcast to the Empire she said: "I declare before you all that my whole life, whether it be long or short, shall be devoted to your service." She has kept that promise; never once has she faltered, and nor will she.

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