VIENNA, April 4 -- As construction crews churned up dirt to renovate a Vienna soccer field last October, they happened upon an unprecedented find: A heap of intertwined skeletal remains in a mass grave dating to the 1st-century Roman Empire, likely the bodies of warriors in a battle involving Germanic tribes.

On Wednesday, after archaeological analysis, experts at the Vienna Museum gave a first public presentation of the grave - linked to "a catastrophic event in a military context" and evidence of the first known fighting ever in that region, AP reports.

The bodies of 129 people have been confirmed at the site in the Vienna neighbourhood of Simmering. The excavation teams also found many dislocated bones and believe the total number of...