THEY died 4000 years ago and, for as long as a century, some have been in the care of Aberdeen University.

Now, the skeletons of 23 men and women have been transferred to Sheffield to help reveal the lifestyles of those who lived in the north-east during the early Bronze Age.

Their bones will be the first to be analysed in a pounds -530,000 investigation taking place at Sheffield University.

In a project funded by the Arts and Humanities Research Council, the latest analytical techniques will be used to answer questions which have intrigued generations of anthropologists and archaeologists.

Housed at its Marischal Museum, Aberdeen University's collections of pottery from prehistoric graves, and their associated skeletons, are among the most important in Britain.

Since the nineteenth century, experts have argued over whether the appearance in Britain of burials with pots - or "beakers" - marked the arrival of continental migrants around 2400-2200BC.

These ancient people have been variously credited with introducing metalworking to Britain, spreading the IndoEuropean language group and building Stonehenge.

In recent decades, many prehistorians have argued that the changes in material culture were due to the introduction of a "beaker package" rather than a wave of immigration, but isotope results from the skeleton of the Amesbury Archer, found near Stonehenge, indicate that he grew up in Continental Europe.

Neil Curtis, Marischal's senior curator, said: "Some of these skeletons have been in the university for more than 100 years, where they have been studied and curated by generations of anatomists, archaeologists and curators.

"It is very exciting to be the first museum to take part in this major research project using new scientific techniques to discover more about people who lived in the north-east thousands of years ago."

The research is being carried out jointly by Sheffield and Bradford Universities with the British Geological Survey and partner museums, and will concentrate on four areas - the north-east is the first to be studied because of the size of the Marischal collection and its quality of preservation and documentation.

Professor Mike Parker Pearson, of Sheffield University, who is leading the research, said: "The long tradition of research on the beaker people in Aberdeen, and the quality of the collection makes it the perfect one to start with."

The project will include the analysis of strontium, oxygen, lead, sulphur, hydrogen, carbon and nitrogen isotopes in teeth to study the movement of people during their life as well as their diet.