A finding of murder was out of the question; Rudolf, after all, was heir to the throne. At first there was even no mention of suicide, out of fear that the church would not permit a proper burial. Rudolf’s death was attributed to poison at the hands of his enemies, or to natural causes.

Because Rudolf was unhappily married to Princess Stephanie of Belgium, no public mention was made of the teen-age baroness. Her body was spirited away and secretly buried.

Finally, the emperor informed the Pope that Rudolf had committed suicide in a “deranged state of mind,” thus allowing a Catholic burial in the imperial vault in Vienna.

The mystery gave rise to much speculation about the circumstances surrounding the deaths, much of it emphasizing the romantic aspects of Mayerling. Not until years later, on the death of Franz Josef in 1916 and the crumbling of the Hapsburg Empire, did the details became widely known.

But because the incident had been so shrouded in secrecy and deceit, conflicting versions endured.

This year, for instance, Clemens M. Gruber, an author and opera archivist, published an account called “The Fateful Days of Mayerling.” In it he argues that Rudolf died in a brawl following a bout of drinking. In Gruber’s view, Marie’s relatives forced their way into the lodge and Rudolf drew a revolver, accidentally shooting the baroness. He is then said to have been killed by one of her enraged relatives.

Attempts to exhume the body of the baroness from a nearby cemetery have been blocked by members of her family.

Another writer, Gerd Holler, who is also a physician, says in his book, “Mayerling–New Documents on the Tragedy 100 Years Afterward,” that Rudolf had arranged an abortion for Marie, who was reputedly three months pregnant. Holler contends that she died in the process and that Rudolf committed suicide.

Empress Zita, who died last week at the age of 96 in a Swiss convent, argued that Rudolf was murdered by French political enemies of his father. She was the consort of Karl I, the last emperor, and grand nephew of Franz Joseph.

Most scholars now prefer the version offered by historian Brigitte Hamann in her book, “Rudolf, Crown Prince and Rebel.” Hamann, who took part in a recent international conference on the incident at Mayerling, said in an interview:

“He was a poetic young man and brooded a lot. He was ill with syphilis and felt guilty that he had infected his wife. They had no children. The reason for all the confusion was the cover-up by the Imperial Court…  The fact is that Rudolf was a very nervous, sensitive man who flirted with suicide more than once.”

She said that recently discovered documents show that Rudolf proposed the idea of a love murder-suicide to another woman, a prominent courtesan, Mizzi Kaspar, but that she refused.

According to Hamann, the Baroness Vetsera, who was in love with the increasingly despondent Rudolf, was more susceptible to the love-death idea.

“There is no question,” she said. “Rudolf shot the girl and then himself.”

After the deaths, the emperor ordered the hunting lodge at Mayerling razed and a Catholic convent built in its place. It still stands, and the Carmelite nuns there still pray for the souls of Rudolf and Marie.