The streaming service announced Tuesday that principal photography on the project had begun. It also revealed Johnny Flynn, Ben Chapln, Ken Stott and Monica Dolan had joined the film's ensemble.
Moira Buffini wrote the screenplay for the adaptation of John Preston's book. Simon Stone is directing the movie, which is slated for a 2020 release.
"As WWII looms, a wealthy widow hires an amateur archaeologist to excavate the burial mounds on her estate. When they make a historic discovery, the echoes of Britain's past resonate in the face of it's uncertain future," a press release said.