LONDON (AP) _ John Major, the youngest and fastest-rising British prime minister of the 20th century, epitomizes the virtues of self-reliance and initiative preached by his predecessor.

Major described himself as a Thatcherite but insisted he was his own man.

''I am not running as 'Son of Margaret Thatcher.' I am running as myself, with my own priorities and my own program,'' Major said over the weekend.

He reaches the highest office in the land 11 years after entering Parliament, without leaving a trail of bruised and resentful enemies. And he came all the way up from poverty without so much as a university education.

Former Defense Secretary Michael Heseltine mounted the successful challenge to Mrs. Thatcher in the Conservative Party that caused the prime minister to abandon her office. But Mrs. Thatcher endorsed Major to succeed her and in the three-way fight for the party leadership and the prime ministership, it was Major who had the votes to defeat Heseltine and Foreign Secretary Douglas Hurd.

Softspoken, bespectacled and often referred to as ''the gray man,'' 47- year-old Major has none of the obvious qualities associated with the political high-flyer.

But Mrs. Thatcher saw in him a sharp mind, political judgment and the conciliator's talent for negotiation.

She saw him as ''a man of the people,'' her aides said, and even his opponents say he's a nice man.

He appeals to the right wing of his party with free market economic views, and to the left wing with his sympathetic outlook toward Britain's underprivileged.

Even for the new breed of Conservative who broke into the ranks of Oxford and Cambridge-educated Tory privilege, Major has an unusual background.

The son of a sometime circus performer and actor, he left school at 16, worked as a laborer and spent eight months on welfare before he started his successful banking career as a clerk at age 18.

Tall and deliberate, Major has neat gray hair, clean-cut features and a quiet manner of speech nearly free of the inflections of class and geography that still pigeonhole so many Britons.

He sees increased social mobility as ''one of the greatest achievements of the last 10 years,'' and says his goal is ''a genuinely classless society in which people can rise to whatever level that their own abilities and their own good fortune may take them.''

The contribution of blue-collar workers should be respected, he says.

''We will need the practical manual skills of people in the future and we should recognize those for what they are - a very genuine talent.''

Once asked if regretted not having gone to university, he said ''not a bit.''

''It has been of immense value to me to have been on the other side of the fence and to know what it was like to face a few difficulties, and I don't regret any of that.''

Besides the broad electoral appeal of his background, Major's greatest practical asset is his financial experience as a banker, chief secretary to the Treasury and lately as chancellor of the exchequer during a difficult year for the economy.

Major climbed swiftly through Standard and Chartered Bank, where he was an executive for 14 years before entering national politics.

His lack of expertise in foreign affairs is regarded as a weakness - he spent only three months as foreign secretary - but he has indicated the veteran Hurd would stay on to head the Foreign Office.

Major's stance on the Persian Gulf crisis is unlikely to differ greatly from Mrs. Thatcher's. On Europe, he says he is convinced Britain will be able negotiate an outcome on political and monetary union that will be acceptable to the European Community and to Parliament.

Elected to Parliament in 1979, he entered the Cabinet in 1987 as chief secretary to the Treasury. From July to October 1989 he was foreign secretary, and when Nigel Lawson resigned as chancellor of the exchequer in October, Major replaced him as the nation's top treasury official.

Major started life in the comfortable suburb of Cheam and went to Rutlish Grammar, a state school for bright children.

When he was 11 the family, including two brothers and a sister, moved to the tough south London neighborhood of Brixton following ''an injudicious investment'' by his father.

He speaks with affection of his father, who was 66 when John was born and soon began losing his eyesight.

''I used to walk with him a lot so he wouldn't trip over curbs and what have you,'' Major once said. ''He was a wonderful talker. ... I still think he was the finest raconteur I have ever heard. He had such a wealth of experience and a range of interests.''

The family lived in a cramped apartment, cooked on a gas burner on the landing and shared a bathroom in the hall with other tenants.

The home was five minutes from the Oval, one of the hallowed sporting grounds of England, where Major acquired a lifelong devotion to the game of cricket.

He can no longer play, however. During a posting in Nigeria with the bank his left leg was so badly injured in a car crash that he nearly lost it.

''My leg doesn't permit me to run,'' he said. ''If I bend it I'm likely to go base over apex.''

Major married Norma Johnson in 1970 and they have a daughter Elizabeth, 19, and a son James, 15. Mrs. Major, an opera-lover, is the author of a biography of the singer Joan Sutherland.

An expert cook and dressmaker, she likes a quiet family life.

''I am very fulfilled by domesticity and I don't feel ashamed or guilty about that,'' she says.

The post of chancellor carries with it the prize of 11 Downing St., the house next door to the prime minister, but it was never home to the Majors. Mrs. Major stayed home in Great Stukeley with the children and her husband came home on weekends.