Scientists say seven skeletons found in a mass grave in Croatia were most likely Roman soldiers who lived 1,700 years ago.

The male skeletons, all with various injuries, were found “completely preserved” during excavations in 2011 at the site of the Roman city of Mursa – modern-day Osijek – in Croatia’s far east, a new research paper says.

Mursa was conquered by the Romans during the first century BC and became a large settlement that was also an important centre for trade and craft.

Now, researchers from several European archaeological institutions have been able to determine not only when the men lived, but also how they may have died.

According to the paper, the men in the grave were aged between 36-50 years old, taller-than-average in height, and were “robust” individuals. Their diets were mainly vegetarian, but some had also indulged in a little meat and seafood.

All showed various healed and un-healed injuries, including those caused by blunt force trauma, and there were puncture wounds on two of their torsos, which the scientists believe were likely caused by arrows or spear tips.

All of the men were suffering from some kind of “pulmonary [affecting the lungs] disease during the final days of their lives”.

DNA analysis has also revealed the men had a mix of ancestry and that none appeared to be from the local area.

The paper noted that the Roman Empire was a particularly violent era and that Mursa was involved in several conflicts.

The researchers believe the men were likely victims of the ‘Crisis of the Third Century’, most probably the battle of Mursa from 260 CE, when there were “numerous battles fought between various claimants to the throne”.

The paper states that the pit the skeletons were found in would have originally been a water-well – several of which have been discovered in the area.

It notes that mass burials and mass graves were “not a customary way of interring the dead in the Roman Empire”, and were mostly used in extreme situations and mass casualty events.

Given the various angles the skeletons now lie, the researchers say they were “most probably thrown in” the well before being covered with soil.

Mursa has been of archaeological importance for years, with various ancient civilisation sites discovered in the area.