Once upon a time there was a landlocked French colony in the very heart of Africa called Oubangui-Shari, which was best known to the outside world for supplying platter-lipped women to circus sideshows.

The French left in 1960, and the blaze of African independence celebrations of that year the country declared itself the Central African Republic.

By then the French, in the name of civilization, has stamped out the habit of distorting women's features, so the country was not really known for anything at all.

But last December its ruler, a no-nonsense, much-deccorated former French colonial army named Jean-Bedel Bokassa, 56, decided to declare himself emperor of his 2 million Central African subjects who live in land as big as Texas.

People in Africa and elsehwhere suddenly took an interest in his potentially rich (uranium, diamonds, coffee, cotton) - nations, which much to his annoyance is listed by the United Nations as one of the world's 25 poorest.

Swept aside were the awkward realities of unparalleled financial mismanagement - in part disguised by generous French government aid amounting to a third of the country's $94 million budget - and Bokassa's mercurial penchant for revolving-door governments.

In creating the empire, Bokassa was capping an extraordinary destiny of a man orphaned at 6, educated by Catholic missionaries, an authentic French army war hero who, since seizing has accumulated honors, riches, fame and the love of women.

Athough he bridles at the suggestion, there are those who insist the empire was created to give himself and his erratic rule a sense of legitimacy, continuity and respect that it and so many other African regimes lack.

Was it megalomania or a deep-sealted sense of insecurity that led him - like so many of his African peers - to put his own features on the country's bank notes, build two statues to himself and attach his name to everything from an avenue and a sports stadium to a market, the fledgling university and army headquarters?

To be sure, he defers both to his "spiritual father," President Felix-Houphouet-Boigny of the conservative Ivory Coast, and to his "younger brother," President Mobutu Sese Seko of the neighboring Zaire.

But so taken is Bokassa with honors that he once had an extra-long coat designed to accommodate his many medals, which include one from an international stamp collectors group and another from a French police officers association.

As for his wealth, even those best disposed toward him - and the fear he inspires is sufficient to prevent critics from speaking up - concede that is practically impossible to discern where the rickety state finances end and his impressive personal fortune begins.

His taste in women is eclectic. He is proud of his three wives, 30 legitimate children and considerable number of mistresses.

The two most prominent women in his life are Catherine, a Central African in her late 20s who is known as the empress, and Gabrielle, a beautiful Romanian blonde of similar years. Before the empire's creation, Catherine was entitled La Marechale and Gabrielle was La Presidente.

Despite his moodiness and penchant for the arbitrary, Bokassa's reputation as French-speaking Africa's equivalent of Urgandan President Idi Amin is undeserved. Bokassa's only known foray into gratuitious violence - if executing would-be assassins can legitimately be excepted - involved his decision in 1972 to beat prisoners in public as a warning against a rising rate of theft in Bangui.

At least three prisoners died - and many others were badly injured - in the 10-minute assault in which Bokassa, surrounded by his Cabinet, urged policemen to light into the thieves with clubs and rifle butts. The victims later were left exposed for hours in the unforgiving equatorial African sun.

Not only has he since eschewed such violence - although he still has his citizens arrested on the flimsiest of pretexts - but he has also proved to be remarkably forgiving. There are believed to be fewer than 20 political prisoners. Ministers who sin - especially against the public treasury - are often jailed, but likely to be given even better jobs. Even David Dacko, the president - and cousin - that Bokassa unseated in 1965, has been resurrected. His full presidential salary was restored and he is working as one of the emperor's closest advisers.

Bokassa justified his coup by expelling the Communist Chinese he claimed were undermining the Dacko regime. Last year, Bokassa invited the Chinese back in.

Whatever his domestic shortcomings he has proven himself an adept practitioner of nonalignment in foreign policy. Not only does he maintain good relations with all of his neighbors - but 28 countries maintain diplomatic missions here.

He keeps both an Israeli and an Arab as personal advisers. The Israeli takes care of Israeli diamond interests and South Africa, which invests as much as $4 million annually without getting much to show for it. The Arab has proven useful in attracting such Arab aid as the 45,000 tons of oil Iraq has agreed to give the empire.

Bokassa appears to give up very little in return. A visit last fall by Libyan leader Muammar Qaddafi provoked an instant religious conversion of Jean Bedel into Salah Eddine Bokassa. But, when certain financial promised failed materialize, he reverted to his Christianity ever so briefly before proclaiming himself emperor.

Not everyone in Africa - or for that matter in this sleepy riverside capital - was amused by the imperial decision. Across the continent, newspapers and magazines heaped scorn on the creation of the empire.

Here, opposition was based on the Wester-trained elite's feeling that the outside world would hold the country up to ridicule. (As for the 80 per cent of the citizenry living in the bush, it was assumed that they could not care less if Bokassa called himself king, emperor or president, since Central African notions or power are at best hazy.)

Local opposition took the form of a delaying action by members of the country's single party. They stretched out a planned three-day congress to nearly a month before caving into Bokassa's desire.

In exchange, the party extracted the first - and on paper very liberal - constitution - the country had known since Bokassa seized power and abolished all government institutions in favor of absolute rule.

If most of the country's elite abandoned their republican ideals with remarkable ease, a comparison of the list of government ministers before and after the empire's proclamation demonstrates that the decision was not universally approved.

The exact reasons prompting Bokassa to proclaim his empire have never been spelled out, but foreign and Central African observers were long aware he was toying with the project.

Some suggest he carried out a preemptive strike to prevent some other African leader from inheriting the imperial mantle left vacant in Africa when Ethiopia's late Emperor Haile Selassie was deposed in 1974. There are striking similarities between the coronation preparations now going on here and those the late Evelyn Waugh described in "Black Mischief," his classic description of Haile Selassie's coronation in 1930.

Other observers trace the whole thing to his reverence for Napoleon, hardly surprising in an unabashed Francophile who rose through the ranks in 23 years of French colonial army service.

They note that his official portrait as president for life - which along with field marshal are the most important of the many titles he bestowed upon himself before that of emperor - showed him decked out in the dress uniform of a Napoleonic general, complete with cocked hat.

Yet the emperor dresses simply and never departs from the direct, pungent and often emotional language he learned in the French army.

With his coronation planned for Dec. 4, the emperor recently has emerged from semi-retirement at Berengo, seat of the imperial court 40 miles down one of the country's two main paved roads from the capital. In past months he has withdrawn from the daily business of government, which once involved holding personally 14 ministerial portfolios and signing all government checks.

Bonassa is overseeing every detail of the coronation plans with ministers of the imperial court, who have more power than the Cabinet.

Empress Catherine has been in Paris for weeks making sure that the considerable and complicated orders arrive on time. Ministers commute back and forth from France on similar missions.

No fewer than 23 committees are hard at work planning everything from housing and medical facilities for 2,000 guests to the construction of triumphal arches and telecommunications.

The coronation is expected to cost anywhere from $8 million to $20 million. At government suggestion, three foreign diamond companies each contributed $100,000 apiece and other, mainly foreign-owned businesses are expected to contribute as much as $2 million.

The biggest item is his crown - featuring emeralds and rubies and as many as 8,000 Central African diamonds. The stones are bing rough-cut here before being finished in Paris by an established jeweler. Its market value is estimated at $5 million.

Also on order are a carriage - to be drawn by eight horses - and 130 Norman horses whose Central African riders are being trained in France.

The throne, in the form of an eagle in flight, is being done in France, as is his coronation uniform. It is being made in the town of Dreux by a firm specializing in ceremonial gear.

So far, the emperor's only setback has been a polite turndown to his overtures to the Vatican to have the Pope - or even a cardinal - officate at the coronation.

It was explained that the Pope was too old and frail to travel, although it is probable the Vatican wants no part of the festivities.

Another uncertain starter is French President Valery Giscard d'Estaing, an old Bokassa fan who has indulged his penchant for wild game hunting in the empire. Giscard has a most delicate general elections on his hands next spring and may well decide his presence here could only alienate French voters.

Although no official schedule has been set, it has been announced that Bokassa will crown himself Dec. 4 in the Yugoslav-built covered basketball court seaking 6,000 where he was proclaimed emperor last year.

A religious ceremony will take place later the same day in the redbrick cathedral seating 3,000.

The following day will be given over to a parade featuring the carriage and horsemen, to be followed by a sitdown dinner for the emperor's guests

Although the country's annual per capita income is only $179, few Central Africans have criticized the outspoken for the coronation. Record high coffee prices have proved a windfall which will cover much of the costs.

As a wise, if cynical, Central African noted privately: "If Bokassa didn't waste the money on a coronation it would be wasted on something else."