The Associated Press is reporting that archeologists have uncovered a mass grave with the complete skeletons of 51 horses buried side-by-side, probably the long-forgotten equine victims of a 17th century battle over a strategic Dutch river.
It was the largest known equine burial ground in Europe, although chief archaeologist Angela Simons said that many such sites have probably existed and have been plowed up over the centuries by unwitting farmers.
The archaeological team had been looking for evidence of prehistoric human settlements in the area when they came across the unexpected find.
"From the first shovel, it was horses, horses and more horses," said Angela Simons, of the Hazenberg Company, which was employed by the Dutch government to survey the ground ahead of a construction project.
Initial carbon testing dated the bones to the 17th century, when the Netherlands was still struggling to emerge as a nation.
If the horses were killed in a battle, likely candidates include a fight in 1632 during the Eighty Years' War, when Dutch rebels quartered in Borgharen repelled a surprise charge by the Spanish cavalry.
Another possibility is the 1673 siege of Maastricht by soldiers of French "Sun King" Louis XIV. That battle is considered a milestone in siege warfare, because of how the attacking French used zigzagging ditches to give their soldiers cover from the city's battlements.
No traces of bridles or saddles were found in the shallow 130-foot (40-meter) -long grave, suggesting they were removed. The researchers discovered just one stirrup and several horseshoes.
Evidence suggests they were cavalry horses. Most appeared to be around 4 years old, and their size and bone structure suggests they were for riding, not draft horses.