The chef de cuisine being sick, the order was passed on to a 16-year-old apprentice, the quick-witted Franz Sacher. A chocolate cake was served to the prince's guests which pleased their discriminating palates. The rest is history.

Sacher saw his cake become intimately associated with the imperial city. Today Cafe Sacher Wien is an institution by itself. A classic, traditional coffee-house and the centre of sweet seduction, from where the `Original Sacher-Torte', the house's sweetest secret set out to conquer the world. It has become the most famous torte in the world and the handwritten recipe is a `state secret' of the hotel.

Selling his flourishing inn, Sacher established an exclusive refreshment buffet bar in a neo-renaissance palace, which featured intimate, private dining rooms where one could eat, chat and perhaps flirt in the privacy of the four walls. These legendary rooms were called in the French style, `separees'.

In 1876, Sacher moved into a new building behind the the new Imperial & Royal Court Opera. The ground-floor housed his well-established delicatessen and he opened guest rooms on the second, third, and fourth floors, creating the legendary Hotel Sacher.

A fateful event was waiting in the wings. On a spring day in 1880, Sacher married Anna Fuchs, daughter of a butcher in Vienna's 2nd district. Anna took over the hotel with aplomb, conviction and foresight, becoming the most famous hotelier in the empire, ushering in the `classic' era of the hotel. After her husband;s death, Anna continued to run the hotel with style and conviction. ``The sacher Hotel: that's me and nobody else'' became her personal motto.

One of the earliest guests, Count Apponyi, established a tradition among the Hungarian aristocracy to stay in the elegant new hotel. Soon kings and princes patronised its celebrated dining rooms. The only prominent citizen not to honour the sacher with his presence was the emperor himself. His son, crown Prince Rudolf, however took a personal interest in the wine list, demanding Chablis for himself and his friends. A few hours later he was dead...a tragic suicide with his mistress Maria Vetsera. The mystery remains unsolved.

Hotel Sacher became the stage for all guests of rank and name, including artists like Leo Slezak and Hedwig Bleibtreu, Edward, King of England, and Milan, King of Serbia. Szemere Miklos personified the typical Sacher guest: not only wealthy but also a gentleman of taste and discrimination. Things haven't changed today. The guest list remains remarkable, and the staff is still discrete.

A year after its opening, the Sacher was expanded. Business flourished. Today's lobby then served as the main restaurant, known as the `Hunting Room' in reference to the hunting scenes portrayed on its tapestries. Today's main restaurant, Restaurant Anna Sacher, was the venue of the famous `Chambre Separees', 12 private dining rooms, which could only be entered by their own numbered doors. The waiters always coughed discreetly before serve wine.

One of the Anna Sacher's passions was breeding toy bulldogs, which are today commemorated in a contemporary painting from the cloak room. She also collected famous guests and hung pictures of them, adorned with her personal dedications and signatures on her office walls. They are still hanging there, just off today's lobby.

Though on intimate terms with her illustrious guests, Anna allowed no breach of etiquette and even an archbishop was to kiss the hand of the hostess. It was also considered in bad taste to discuss money in the Sacher's hallowed halls. Whether the guests were Hungarian millionaires or the so-called `Sacher Boys', Anna Sacher often closed her eyes to a certain lack of cash. As long as they were `the right sort of people', she often allowed a signature to be accepted in lieu of hard currency.

`All Europe feels at home in Sacher....' it was rather as if there was a `House Scher' like a `House of Habsburg'. `In this House dwells Austria,' wrote the playwright Franz Grillparzer. In the case of Sacher, it was amended to `In this House all Austria eats'.

Its first zenith lasted 40 years. The end of the First World War and the collapse of the monarchy suggested that the elegant hotel had outlived its time, many of its regular guests gone. Inflation struck. Anna Sacher herself lost her financial sense and became a virtual recluse. She died in 1930.

Anna's personal treasures enrich the hotel. Like her extraordinary collection of signed portraits, and collection of menus-enchantingly illustrated bills of fare once placed in front of famous personalities like Wilhelm 11, the prima donna Marie Renard, Milan of Serbia, and the local beer brewer Dreher. Anna once asked her head-waiter, Wagner, to ask an Archudke dining in a separee to sign a damask table-cloth. He declined and she failed to get the imperial autograph. She tried again when the dapper Otto, brother of Archduke Franz-Ferdinnad, came to dine. He consented and began a remarkable tradition. Since then hundreds of princes and artists have felt honoured to put their pens to this famous cloth and it remains one of the house's great treasures.

The spirit of Anna Sacher lives on. The Sacher has provided extraordinary inspiration to the arts. No other hotel in the world has lent its magic to so many works of art.

Without Anna Sacher, the hotel's fortunes declined. In 1934 it went bankrupt. Two families, Josef and Anna Siller and Dr Hans Guertler and his wife Poldi purchased the ailing enterprise and upheld the legendary hotel's traditions. They renovated and refurbished the house while preserving the rich heritage of decades.

In 1938 Austria lost its independence. When the Second World War began, Sacher again lost many of its regular clients. In 1945, Vienna was occupied by the Soviets. They stabled their horses in the Marble Hall, which once had been the venue of the monarchy's most glittering parties. Then the hotel was turned into the British Senior Officers' Club and it seemed Sacher would never become a hotel again.

In 1951 the Sacher was reborn under Hans Guertler, and once again fully renovated. 18 rooms with baths-n-suite, increased to 40. Multi-storied luxury suites were built over former glass-roof coutyards. The Guertlers' love of art also enriched Sacher as they assembled a great collection of precious oil paintings, engravings, rare antique furniture and tapestries.After Josef Siller's death immediately after the war, the Guertler family bought their share of the hotel, but Dr Hans Guertler died in 1970.

In 1971, the 25-year-old Peter Guertler improved, preserved and conserved the best of Sacher. The restaurant took its place among Vienna's very best with a new, modern kitchen. Nevertheless, the great national speciality Tafelspitz, succulent boiled beef with all the trimmings, is still cooked in the classic way. And, of course, `Original Sacher Torte' continues to delight local and international palates.

On the occasion of the hotel's 100th birthday, the book Hotel Sacher in Vienna was published, which ends with the words: ``Sacher is still flourishing both inside and outside. It is well prepared for the next century.'' Little wonder, the Sacher remains a truly Viennese institution and hospitality landmark.