London: Prince Albert, the beloved husband of Queen Victoria, died in 1861 at an early age of 42, plunging then British Monarch into a deep mourning that lasted for the rest of her life.

Now, 150 years on, the riddle of Prince Albert's death has finally been solved, with a historian claiming in her book, 'Magnificent Obsession: Victoria, Albert and the Death that Changed the Monarchy', that he died from Crohn's disease and not from typhoid fever as Victorian doctors assumed.

The inflammatory bowel condition was not known to medical science at the time of his death just before Christmas in 1841 but is treatable today.

Now, historian Helen Rappaport has spent three years researching the death of Prince Albert, and trawled through contemporary papers, including some buried deep in UK's Royal Archives, and obscure journals, with one from 1993 explaining the cause of death.

"It's time this highly underrated man was given the credit he's due. Prince Albert was King in all but name and had been for many years before 1861. But ironically, his sudden death was the making of Victoria as a Queen.

"Although it took her many years, she did recover from his death, went on to lead the nation and Empire, and set her seal on a whole generation," the 'Daily Mail' quoted the author as saying.

Royal doctors were not certain when they diagnosed the cause of Prince Albert's death and officials blocked the release of any details about his demise. Queen Victoria refused to allow a post-mortem, so it was accepted that her husband had been killed by typhoid.

However, in 1993, an obscure article in a medical journal suggested the Prince may have suffered from Crohn's disease. His worry over son Bertie may have triggered a flare-up, leading to septicaemia and finally pneumonia.