BENEVOLENT and good humoured, the German Federal Chancellor, Dr Helmut Kohl, towers over almost everyone he meets, radiating a sense of fellowship and solid cheer.

During his official visit to Mexico 10 days ago, German journalists noted that he hit it off particularly well with President Ernesto Zedillo, who is a head shorter. The Mexican Foreign Minister quipped that his boss, though overshadowed by his large guest, had found a place in the sun.

Kohl yesterday celebrated the 14th anniversary of becoming chancellor of West Germany three years longer in office than Margaret Thatcher, and much longer than any other elected post war western leader apart from Francois Mitterrand.

He is now unquestionably one of the phenomena of the age. As the political head of one of the most powerful countries in the world he destined to take his place in history as the architect of German unification. With a little luck, he will also preside over the inauguration of European Monetary Union.

Very few political leaders have one, let alone two, major historical events that allow them to show their mettle. Konrad Adenauer, Kohl's great father figure, was comparable in that he re-established West Germany's democracy and economy after the war.

In a few weeks' time Kohl will have served as Chancellor for longer than Adenauer and will be set to break Otto von Bismarck's 19 year record as imperial chancellor in the late 19th century.

It is a sobering thought that if. Kohl does take up the challenge, he will still be about the same age when he finally calls it a day in 2001 as the US presidential challenger, Robert Dole, is now.

At 66, he shows little sign of flagging, and the expectation is that, despite what he allowed Germans to think after his narrow victory in 1994, he will lead the CDU dominated coalition into the 1998 election.

His pre-eminence in German, European and world politics has been a slow burner, and might have failed to materialise without the cataclysmic events in eastern Europe that culminated with the break-up of the Soviet empire in 1989.

Kohl rose to the occasion with an innate mastery of the demands of Germany's new key position in a rapidly changing world. His close personal relations with Mikhail Gorbachev and Boris Yeltsin have been among the enduring elements of stability in the region.

Kohl is an instinctive politician, often flying by the seat of his broad pants. A notable instance was when he overrode the advice of the Bundeshank in 1990 to create German economic union on the basis of an unrealistic valuation of the East German currency. He also, injudiciously, promised a flowering landscape" instead of the highly polluted environment left by the communists.

Critics still hold the decision and the promise against him as examples of rash populism that helped to raise expectations unduly. Six years later, the jury is still out as far as growth and convergence of the two economies are concerned, but the dire consequences that many of his political opponents predicted for his policy in 1990 have failed to materialise.

If he is now unrivalled in domestic politics, driving the Social Democrats to despair as they contemplate another defeat in 1998, and raising concern in his own party over the leadership vacuum when he eventually does go, Kohl has not always seemed indispensable.

Old timers in Bonn remember the sense of deep scepticism verging on hilarity when he became the federal chancellor of West Germany in 1982 after a government crisis that split the SPDIFDP coalition and threw the sophisticated and articulate Social Democrat, Helmut Schmidt, out of office.

Kohl, by contrast, was large and roly poly, and cultivated a simple, directness that sometimes seemed like naively. Banana skins had a tendency of situating themselves under his feet.

Even in a federal state where, by definition, provincialism is the commonest form of political life, his share of it, as a man who had climbed the ladder of Land politics in Rhineland Palatinate, seemed excessive. Among his many strengths, however, is a capacity for party cos setting to the nth degree that would put the most assiduous Fianna Fail ward-heeler in the shade.

"Kohl maintains very close relations with the party barons at district level farmers, successful business people, powerful local civil servants," says a Bonn insider. "He rings them up on birthdays, or when there is something to congratulate them about. These are the people who choose the candidates for election to parliament. A word from him can wreck a promising political career.

He rules by telephone, he knows everybody who matters that is the nucleus of his power. To maintain good relations with the local barons, he uses a very fine diplomatic skill. They can be extremely stubborn about their vested interests, but they a large part of the party machine.

Kohl is a past master at this game, and in the 1980s, before his position was unquestioned, he used this ability to fight off two attempted coups by party rivals who afterwards disappeared from national politics.

A critic of the Chancellor admits that Kohl's ability to learn was underestimated in the early days. "When he was elected we all said, It can't last. The first time he goes on television, everyone will see through him and laugh him out of the place. But he has never stopped learning. That is the secret of his survival."

He has an eighth, ninth or tenth sense for knowing what people want. Allied with enormous energy, drive and lack of self doubt, his instinct rapidly turns a perception of the public's wishes into a blueprint for action.

ON OCCASION, his relentless pursuit of what his antennae tell him of popular feeling has let him down.

In 1990, he was opposed to a quick conclusion of the frontier agreement with Poland, a sensitive issue in Germany, but climbed down when the Allies, led apparently by a resolute Margaret Thatcher, made it clear that there would be no German reunification without it.

"That instinct for what people want made him reluctant to raise taxes to pay for unification, which objectively he ought to have done", the same critic says. It was the reason for the politically popular move in east Germany of fixing a favourable exchange rate for East German marks, against all the advice of the experts.

"But he does have a chance to show that he is a major statesman if he presses ahead with EMU against deep scepticism and doubt among ordinary Germans. If the current savings package keeps unemployment at its present level or reduces it, he could be unstoppable in 1998."

The troubling aspect of Kohl's supremacy in German politics is the lack of any real challenge, either on the government side or among the Social Democrats. "If the English Blair were the candidate of the SPD," says one of his critics, "Kohl would think twice about standing again".

But Lafontaine, Scharping and Schroeder, the famous SPD Troika the first two defeated by Kohl in 1990 and 1994, the third itching to have a go but widely distrusted in his party do not project the image of giant killers.

Picking a successor in the CDU or its Bavarian ally, the CSU, is a fascinating game, fraught with pitfalls and individual prejudice. Kohl's intolerance of rivals and his habit of "punishing" anyone who displeases him have left few obvious runners, with the possible exception of Dr Wolfgang Schtiuble, the CDU's business leader in the Bundestag, who has been confined to a wheelchair since an assassination attempt six years ago.

It does seem certain that whoever attempts to fill those oversize shoes will have difficulty in talking down public scepticism about EMU a good reason for Dr Kohl to keep on target for his date with destiny in 2001.