A team of experts was called to St Michael and All Angels Church in Penkridge ahead of plans for a new annex being drawn up.
Staffordshire-based firm, Commercial Archaeology, carried out a geophysical survey of the northern section of the churchyard, before digging out two 4ft-deep test trenches – where they discovered the skeletons.
They are believed to date back to the late-1800’s when the church underwent renovation. It is thought that bodies were moved from inside the building into the grounds.
Helen Martin-Bacon, director of Commercial Archaeology, said: “What we’ve found is a series of burials, they’re all aligned east to west, so they’re Christian burials.
“There’s a lot of disarticulated bone and we think they are here because in 1880 they lowered the floor of the church by three foot and we think moved a lot of burials from inside the church out here.
“That may not be the case, but it seems the most likely.
“There’s nothing here to identify them, but they are definitely older than living memory and there are no church records.
“Usually we use pottery to date burials, or any materials but we’ve only found one in a wooden coffin, which has some metal plating on the outside.
“They’re not likely to be Medieval – the coffin probably dates that particular body to 18th or 19th century. It’s a mystery and begs the question as to who are these people?”
Around 16 skeletons were uncovered in the trenches and the archaeologists expect that they would find many more if they dug deeper, or in nearby areas.
The dig team was initially hoping to find ancient church foundations. It was hoped the dig would also shed some light on the church’s royal connections.
King Eadred’s nephew King Edgar made Penkridge his capital for three years.
Rev Greg Yerbury said: “When the Mercians beat the Saxons they celebrated at a nearby church – possibly here on this site.
“For reasons that remain all mysterious, this land certainly housed a royal chapel from 950ish all the way through 1840.
“No-one knows why a church in the middle of nowhere would be a royal chapel. It was a large authoritative place for unknown reasons. I personally think the old church was more likely to be closer to the bowling green, not the north side of the church.”
Ms Martin-Bacon added: “If you look at a map of the area, the roads form an enclosure around this site and it would have been an important religious settlement in the Saxon period, with clergy men living on it, with brew houses, barns, workshops – potentially this whole area would have been very busy.
“We were hoping to find structural remains of the old saxon church here but that’s not here. It’s here somewhere, but perhaps not in this exact location, or much deeper down. As archaeologists you want to keep digging, but we won’t be here.”
The church commissioned the archaelogical survey after plans were put forward for a new hall, connecting to the church.
The survey carried out by the company used a method known as ground penetrating radar. It records reflected radio waves that are pulsed into the ground as a radar antenna is dragged along the ground surface. No further examination of the skeletons will be made, with the aim to preserve them.
Following the excavation a heritage report will be issued before plans can be made to build the annex, which the church expects could take several years to plan and build.
The first official recorded grave at St Michaels dates back to 1572 – although burials at the site took place in the Medieval era, according to experts. The church was built in the 13th century.