Ancient Christians lived alongside followers of mysterious faith 1,500 years ago, archaeologists say

Archaeologists in Iraq recently uncovered evidence suggesting that Christians co-existed with a now-little-known religion. 

The discovery, announced by Goethe University Frankfurt in Germany, was made public in December.

Archaeologists were unsure what purpose the complex had in ancient days - until they found five square pillars that "suggested that it might be a church," the university release said.

"Geophysical investigations had revealed more walls underground, so that this 'church' was initially believed to be part of a larger monastery," the release also noted. 

Pottery with a Maltese cross was also recovered there.

The Zoroastrians were subjects of the Sasanian Empire, a major Persian empire that ruled from around 224 A.D. to 651 A.D. 

There are some 100,000 Zoroastrians practicing the religion today.

The proof of Zoroastrians at the site is "more indirect," said Alexander Tamm, a professor at Friedrich-Alexander University of Erlangen-Nuremberg. He co-led the excavation.

He added, "If one thinks this through further and assumes that a small military unit may have been stationed there… these individuals were most likely Zoroastrians."

It's not news that these two religions had intermingled in northern Iraq, Tamm said.

"Religious diversity was common," the archaeologist noted.

For those unfamiliar with Zoroastrianism, Tamm said it differs markedly from Christianity.

"Zoroastrianism includes multiple deities, whereas Christianity, of course, has only one God," he said. 

Tamm also cited "significant differences" in customs, particularly in burials. Zoroastrians would bury their dead in rock-cut niches or vessels to prevent direct contact with the earth.

"Christians, however, did exactly that: They buried their dead in the ground. This could certainly have been perceived as a major affront to Zoroastrians."

Despite that tension, Tamm pointed to evidence of people "adapting to one another, to some extent."

He said, "They likely respected each other's customs, even when those practices partially contradicted their own religious teachings."

"We really had very few indications of what to expect," the expert said. "We had assumed we might uncover a small village."

"There is still a great deal left to excavate," he said.