piece is a clue to the growth of the early church. using carbon dating and dna techniques, scientists hope to build a map showing the crucial role played by relics in the spread of christ's message. [ speaking in foreign language ] >> we're obviously aware of the fact that the vast majority of the material of the relics that we'll be testing are probably not going to fall into the period which historically we would expect, but this is just the first step in a big project in which we're looking at other similar relics, getting dates for them, getting reliable scientific data from them to find out more about who these people were, where they came from. >> the ambitious project to draw that historical map across europe begins in bulgaria in 2010 with an excavation that makes headlines around the world. buried beneath the ruins of a 5th-century orthodox christian monastery dedicated to john the