Figure of Eadgyth from 1510.

She ate lots of fish, rode frequently, may have suffered from a disease or an eating disorder at 10 and regularly moved around the chalky uplands of southern England, presumably as she followed her regal father around his kingdom.

Analysis of remains found in a German cathedral have not only confirm they belonged to the granddaughter of the English king Alfred the Great but also given an insight into the life and times of a Saxon princess.

Eadgyth (roughly pronounced Edith) was packed off by her brother as a diplomatic gift to Otto, the king of Saxony, more than 1,000 years ago. She died aged 36 and her remains were thought to have been lost forever until body parts were found wrapped in silk in a lead coffin two years ago.

Earlier this year the skeletal fragments were brought back to Britain, and experts at Bristol University will today spell out why they are sure the remains are those of Eadgyth and what they know of her life.

Mark Horton, an archaeology professor at Bristol, said it was "incredibly exciting" to confirm that the bones were the princess's and to find out more about her life.

"This period was when England was really formed," he said. "We don't know much about these dark age queens and princesses. This has created a connection with one of them."

Eadgyth was born in Wessex in 910 into one of the most powerful families in England. She was daughter of Edward the Elder, and half-sister to Athelstan, the first king of all England.

In 929 Athelstan sent her and her sister, Adiva, off to Otto and invited him to take his pick, sealing an alliance between two of the rising stars of the Saxon world. Eadgyth was chosen and the couple had at least two children before she died in 946.

Chroniclers of the time paid tribute to her beauty and recorded how devoted Otto was to her. She was also praised for her good works.

Eadgyth was buried in a monastery, but her bones were moved several times before being interred in an elaborate tomb in Magdeburg Cathedral in Saxony-Anhalt in 1510.

It had been assumed that the bones had vanished and the tomb was empty, but in 2008 German archaeologists opened it and found it contained a lead box holding skeletal remains.

The challenge for the archaeologists was to show that the remains, which had been moved so often, and could easily have been substituted by others, were those of Eadgyth.

A study of the bones at the University of Mainz confirmed that the remains belonged to a single female, who died between 30 and 40. One of the femur heads suggested the individual was a frequent horse rider, hinting at her nobility.

Analysis of the bones suggested she enjoyed a high-protein diet, including a large quantity of fish, which again suggested she was an aristocrat.

It proved impossible to extract DNA from the remains – and the problem then, anyway, would have been fbut finding a sample of a descendant to try to match them to. Unfortunately vital parts were missing, including hands, feet and much of the skull. But crucial scientific evidence came from the study of the teeth preserved in the upper jaw.

A technique measuring the strontium and oxygen isotopes mineralised in the teeth as they are formed was used. The value of these isotopes depends on the local environment and its underlying geology – this valuable data is effectively "locked into" the teeth.

Studying tiny samples of enamel allowed scientists to work out that she must have spent time in Wessex's chalky uplands.

Horton said it had been possible to map almost month by month where the woman had lived as a child and were able to check this against what is known about Eadgyth's youth. But the findings added detail to what was known.

He said: "Eadgyth seems to have spent the first eight years of her life in southern England, but changed her domicile frequently, matching quite variable strontium ratios in her teeth. Only from the age of nine, the isotope values remain constant.

"Eadgyth must have moved around the kingdom following her father, King Edward the Elder during his reign. When her mother was divorced in 919 – Eadgyth was between nine and ten at that point –both were banished to a monastery, maybe Winchester or Wilton in Salisbury."

Trauma was also indicated in her skeleton around this same age, suggesting a dramatic change in her circumstances. She may at this time have suffered a disease or eating disorder, said the scientists.

More tests will be carried out on the material found in the coffin but the princess will be laid to rest later this year when the bones are reburied in Magdeburg Cathedral.