Jack The Ripper, undoubtedly the most famous serial killer in the world, spread terror throughout London in the last years of the 19th century.

Since then his crimes have been pored over by untold numbers of experts - yet nobody has ever convincingly unmasked this notorious figure.

Instead conspiracy theories, myths and fantastical speculation have concealed the chilling facts of the case.

So did 'Jack The Ripper' really exist? or is he a media invention?

Most experts agree that one man was behind at least four killings. Others think there were possibly eight.

A metropolitan police investigation collected eleven separate murders between 3 April 1888 and 13 February 1891 under the title of the "Whitechapel murders".

The first recognised 'ripper' killing took place in the early hours of Friday, August 31, 1888.

Mary Ann Nichols (above), known as this polly, was probably in her early 40s when she met the ripper while soliciting in Buck's Row (now Durward Street) in Whitechapel.

Her body was first discovered by a delivery driver at around 3.45am in the entrance to a stableyard. Her throat had been cut twice, severing the blood vessels on both side of the neck.

She also had a deep jagged wound across the left side of the stomach and three or four similar cuts on the right side.

Eight days later a second prostitute, Annie Chapman (above), 47, was discovered in the back yard of 29 Hanbury Street, Spitalfields, at around 6am.

Again her throat had been severed twice with a sharp knife, so deeply it had cut into the spine.

The killer had also slashed open the abdomen, cut away the intestines and placed them on the victim's shoulder. Her uterus had been removed along with part of the bladder.

Such was the surgical skill used that the doctor who performed the postmortem believed it would have taken at least 15 minutes and an in-depth knowledge of anatomy.

On September 27, the central news agency received a letter signed 'Jack The Ripper'. It is now thought to have been written by a journalist desperate for a story.

The note began 'Dear boss, I keep on hearing the police have caught me but they wont fix me just yet. I have laughed when they look so clever and talk about being on the right track.'

It added: 'I am down on whores and I shant quit ripping them till I do get buckled. Grand work the last job was. I gave the lady no time to squeal.... the next job I do I shall clip the ladys ears off and send to the police officers just for jolly wouldn't you.'

Three days later on the Sunday morning two prostitutes were murdered within the space of 45 minutes, although there is some doubt as to whether they were the work of one man.

Elizabeth Stride, a 45 year-old woman of Swedis origin, was killed in Dutfield's Yard of Berner Street (now Enriques Street). Her throat had been cut once from the left although there was no other mutilation.

One witness, known as Israel Schwartz, claimed to have seen one man throw the victim down on the street while another watched, lighting his pipe. Mr. Schwartz walked off after being spotted by the second man.

Louis Diemschutz, jewel salesman, discovered the body when he drove his cart into the yard at around 1am, possibly interrupting the ripper before he could finish.

Over in Mitre Square in the city of London, the body of 46 year-old Catherine Eddowes was found by a policeman in Mitre Square.

Her throat had been cut, her abdomen slashed open and her intestines placed over the right shoulder. Her left kidney and most of the uterus had been removed.

In contrast to other victims, her face was also mutilated: there were cuts through both eyelids, the bridge of the nose, tip of the nose, upper lip, and both cheeks.

Part of her bloodspattered apron was found in nearby Goulston Street, Whitechapel, below graffiti on the wall reading: 'The juwes are the men that will not be blamed for nothing.'

The next day a postcard was sent to the central news agency referring to a 'double event.'

More disturbingly about two weeks later a parcel containing half a human kidney preserved in wine was sent to George Lusk, the head of a vigilance committee in Whitechapel.

A note (pictured above), which claimed the organ had been taken from Catherine Eddowes, began: 'From hell...

'I send you half the kidney I took from one woman and prasarved it for you tother piece I fried and ate it was very nise....'

It was signed 'Catch me when you can.'

Finally on Friday, November 9, Mary Jane Kelly, an Irish-born 25 year-old prostitute, was murdered in her room at 13 Miller's Court, Dorset Street, Spitalfields.

She was last seen at around 2am with a man described as of jewish appearance, with a large dark cloak, felt hat, white collar and black tie, light boots and a gold seal hanging from his waistcoat.

Her body was discovered when the rent collector arrived at 10.45am and looked through the window.

This time the killer had enough time to not only cut her throat but completely disembowel her, cut off the breasts and mutilate the face beyond recognition.

The uterus, kidneys and one breast were found under her head and the other breast by her right foot. The liver had been placed between her feet, the intestines on her right side and her spleen on her left. Flaps of skin taken from her stomach and thigh were placed on the bedside table. Her eyebrows, nose, cheeks and ears had been partly cut off.

Her heart had been removed and taken away from the scene.

All five murders were carried out at night and each one increased in violence except that of stride.

Although there were four other 'Whitechapel murders' they bear no real similarity to the ripper crimes. It is believed the killer suddenly stopped, either having died, emigrated or been incarcerated.

While several suspects have been suggested, including even Prince Albert and the painter Walter Sickert, neither the original police investigation nor later research has unearthed a convincing candidate.

Despite, or possibly because of, the failure to catch the culprit, the killings created an international media sensation in the cheap newspapers of the day.

Even now, after over a century, he remains one of the most notorious figures in history.