For purpose of quickly sketching Lord Carrington's spectacular personal triumph, it may be said Rhodesia was as hopeless a case as ever trundled down the international pike.

The black majority, long subjugated, increasingly asserted claims to life, liberty and the hope of cash, and the old-line white settler families were nervous at the thought of having everything seized. Meanwhile, a biracial hodgepodge of a government seemed (to some) to offer an easy way out. Except that guerrillas were fighting.

Enter Lord Carrington, the foreign minister of Great Britain, whose prime minister, Margaret Thatcher, was once described as the world's only lady bull who carries around her own china shop.

Thatcher, whose great interest has always been domestic politics, regarded the black guerrillas as communist terrorists and wanted no part of them in Rhodesia or anywhere else.

It was Carrington's preliminary task to assist her to the view that these people had to be dealt with.

Lord Carrington sensed the existing biracial government was not going to work, was not going to win the civil war in the long run, and he therefore concluded the only way out was to bring the biracial government and the guerrillas together and hammer things out.

The poet Marvell once spoke of some project very like Rhodesia: "It was begotten by despair upon impossibility."

His lordship, who has learned over the years to sit on a sofa and be comfortable there, glanced out the morning room windows of the British ambassador's house at the glory of an English lawn right here in Washington and began:

"I was not sanguine," he said.

Now sanguine, indeed. Years of effort had failed to settle anthing in Rhodesia-Zimbabwe, and now it had come to virtual civil war, involving guerrillas based (some of them) in adjacent countries.

Any man would have been justified saying it was hopeless, and the best thing was to walk away and leave that part of southern Africa to bloodshed, chaos, or anything else that chose to happen.

"There was not a great chance of success," he said, "but there were a few favorable things. Both sides had had long enough to be a bit worn out, and nobody wanted everything to bust up. One thing I accomplished was to make a variety of people call me a bastard."

He nevertheless is credited with turning the prime minister around so she stopped calling the guerrillas names, and then (with no idea of the outcome) Carrington began issuing ultimatums at what he hope were well-chosen times, and to the astonishment of the warring sides and of the world in general, a new government was reached, with peace.

"Now you may see, in that country, people who said and did the most appaling things to each other laughing over a drink."

He takes no personal credit for persuading Margaret Thatcher to follow his policy. She simply saw it for herself. And as for the stunning triumph of bringing African factions together, he also reminds us we must never forget the great roles of Mr. Tim Tommy-fitz or others (it is possible he made up the names on the spot) without whom etc., etc.

Lord Carrington does not, however, remind you of those Hollywood types who accept kudos by thanking the cab driver, makup man and so forth. He is clearly delighted a policy has worked and a nation has been spared. Compared to that, he cannot imagine his own role, hyowever central, is of much importance.

On a routine visit, he came to Washington to see one secretary of state, but saw another this week, whom he had never met. Delighted. He was subject of "Issues and Answers," a television program, where someone asked him (in effect) what he thought of the presidential chances of Reagan. Or was he too diplomatic to say?

"I'm not too diplomatic to say," he said. "I am too wise to say." (Laughter.)

Some Americans, many of them Democrats, believe the republic will drop to the bottom of the ocean if Reagan wins. Carrington said the British, some of them, also foresaw utter ruin when his prime minister, Thatcher, was elected. An yet the island still swims, you might say.

Actually it does not swim very fast, and the Conservatives now in power seem keen to speed it up. It offends British pride to see Europe generally rich with bustling economies while Britain lags.

Carrington once announced it simply will not do to keep on "locking ourselves away, unsure of ourselves, increasingly poor, fiercely nationalistic, but with our sovereignty locked up in a deed box."

No sir. The British must increasingly mix with Europe and gain greater status there.

Carrington is not lordly but not timid either:

He was keen to sit outdoors in the glorious spring morning, the azaleas all in bloom, the beech tree planted by the queen ready to burst into leaf, but the British ambassador, Sir Nicholas Henderson, intercepted him. Too beastly hot, the ambassador said, and Carrington gave no hint it was just right out there for him. He sat in the morning room as directed, but did assert himself by refusing orange juice.

On another occasion, when he was First Lord of the Admiralty, he attended a great ceremony aborad a battleship, accompanied by an aide. The aide went in first and was mistaken for the First Lord. Carrington said nothing, and it was only later that people figured out the high honors and ceremonies had been wasted on his lordship's sidekick.

A well-built, lean, blue-eyed aristocrat of 61, Carrington was once seen on television holding the cap of maintenance for the queen.

"Cap of maintenance?Surely that's not English," it was suggested.

"Totally English," he said complacently. "There was once a king who thought the crown was too heavy, so he had an ermine-trimmed cap made. He would remove his crown and put on the soft and comfortable cap. By this means he maintained his regal power without wearing the heavy crown.

"So on certain occasions I stand there with a pole holding the cap of maintenance. Some day the queen may signal me, and I'll be there ready with the cap."

The first time he held the cap, he was gratified that a critic said he looked as dignified as a man can look, standing around with a cap on a pole. He believes himself capable, he said, of these high matters of state.

He is the fifth Baron Carrington, a title granted his forbear by George III.

His own name is Peter Carington, but the title has an extra "r" in it because of what we might call a transmission error at the College of Heralds who drew up the patent.

He attended Eton, on the playing fields of which the battle at Waterloo is supposed to have been won, a famous school that has not gratuitously assumed responsibility for the decline of Empire.

Carrington inherited the title and his place in the House of Lords at the age of 19. After Eton he attended the Roylal Military "college, Sandhurst, and entered the elite Grenadier Guards, serving with distinction in World War II and winning the Military Cross (second-highest combat decoration in Britain) for sevice at the battle of Nijmegen in Holland.

At the age 27 he resigned from the Guards and took up farming on his ancestral acres and his seat in Lords. He once observed that he is the product of privilege but thought that should not bar him from the joys of work or advance in government.

He rose gradually, not meteorically, up to the highest positions in defense, energy, and now foreign affairs.

Befre he left his post as defense minister in 1974 to become minister of the Department of Energy, Carrington had already become one of the most trusted advisers of then-Prime Minister Edward Heath. It was widely believed that Carrington was consulted not only on questions lying within his specific jurisdiction but on almost every important question of government.

This was a far cry from his political start in 1951, when he was 33, as joint parliamentary secretary to the agriculture ministry, though it was remarked at the time that he was one of the youngest men in Churchill's government. Then from 1954 to 1956 he was parliamentary secretary for the defense ministry.

It was after this that he went to Australia as high commissioner (ambassador) and three years later he returned home to become First Lord of the Admiralty.

He became the leader of the House of Lords in 1963.

His friendship with Heath developed gradually over some years. Among other things, Carrington was good at raising money for the Conservative Party, and when it came to power in 1979, Carrington became defense minister.

More recently a wing of the party headed by Margaret Thatcher replaced Heath. To the surprise of some Thatcher named Carrington to her Cabinet as foreign minister, despite his long and close association with Heath. It is believed that since Carrington's success negotiating difficult settlements in Africa the prime minister has come to rely on him more and more.

He believes greatly in giving things a go, but you have to believe a policy is right and also workable, then you have to be a pragmatist and bend here and there. Sometimes you push hard, sometimes you fall back as gracefully as possible, and usually, perhaps, you keep your mouth shut.

The art, of course, lies in knowing when to do all of the above. An art rarely mastered, which is why Carrington is somewhat suitable for bronzing already.

He glanced at his dove-gray silk socks (no wrinkles there) and alluded to the abuse he took from all sides during the Rhodesian negotiations.

"But if you hang on a bit, you'll be an elder statesman," it was suggested to him.

"Oh, good," he said. "Then the memories can become very selective."

Churchill, after all, managed to make everybody forget Gallipoli and other disasters of his life, remembering only the greatest moments.

Carrington's house is near Chequers, the prime minister's country house once occupied by Churchill.

"My wife has made a beautiful garden," he said. "The English are very good gardners," he volunteered, "and I take credit for the garden sometimes, but my wife really did it all. We have a rough-haired dachshund and a smooth-haired dachshund. They are very bad dogs," he said, with a sparklingly smug smile, "and sometimes bite, and give the police much trouble." s

"Perhaps owning lawless mutts is more fascinating even than your triumphs," it was suggested.

"I would hate to find out later that the foreign minister goes home at night and kills little baby cats," he was told.

"Certainly not," he said, "I only do that in the mornings."

He has found music a succor in times of uneven stress, and goes to the opera whenever possible.

"I fell into music in Australia.Canberra used to be called a cultural desert, though I always liked what one Australian said, that they are very cerative in irrigation.

"Which reminds me once I met the ambassador from Nationalist China there -- I was high commissioner or ambassador from Great Britain -- and I greeted him at the airport and said there was a performance of 'Hamlet' that night that he might enjoy seeing.

"He said no, thanks all the same, he'd already seen it in 1936.

"I very much liked the Australians, by the way, and was never happier than when I was allowed to deal with them directly. Yet for an ambassador in Canberra in those far-off days, ah, hmm."

"You mean it was not Paris," he was prompted.

"So it was then I turned to records," he said, "and discovered music.

For a man celebrated for his daring and his brinkmanship, he is generally in favor of calmness and not going off half-cocked.

He said there are plans for all such emergencies as the taking over of British embassies, but in general a policy of patient cooling off seems to work best.

Though he thinks the United States had every right to launch the rescue attempt in Tehran.

Indignation, he clearly feels, is not enough. In the case of the American hostages, he said, you have to remember the Arab-Israeli tangle and the Soviet-Afghanistan situation, as well as the American-Iranian impasse. What is done in any of the three cases, he said, has an important rub-off on the other two.

Despite his feeling that patience and careful watching is generally a better approach than violence to answer violence, he said after the Special Air Police in London yesterday killed three terrorists that once the terrorists actually killed a hostage and displayed the body, 'We thought it was enough."

His central role in advocating a neutral Afghanistan appears to be based on his twin notions, one pragmatic and the other bedrock -- that the Russians must withdraw from that occupied land, and a way should be found to let them save a bit of face.

Television crews showed up at the house to braodcast an interview, and the ambassador sat on the sidelines while Carrington was dusted and squirted and generally touched up so his temples wouldn't shine under the bright lights. Someone said man is born to great indignities he cannot avoid and the ambassador said:

"True. And I have noticed they are very good at putting that stuff on you before the show. But they never offer, afterwards, to take it off."