A Life of Pliny

"Appointed imperial legate to Bithynia, in what is now northern Turkey, Pliny was taken aback by how many Christians were there" and decided to "eradicate them or make them recant" but Trajan (the Roman emperor) "counseled moderation."

Bithynia was a significant part of what's today Turkey:

https://upload.wikimedia.org/wikipedia/commons/f/fd/1stMithr...

For a time reference Pliny the younger died around 113 CE (second century).

Eventually, whole 18 centuries later, most of the Christians in Turkey were "cleaned" at end of 19th and the first part of 20th century:

https://www.hup.harvard.edu/catalog.php?isbn=9780674916456

"The Thirty-Year Genocide, Turkey’s Destruction of Its Christian Minorities, 1894–1924", Benny Morris, Dror Ze'evi, Harvard University Press 2019

“Three Turkish regimes were involved, from the Ottoman Empire to Ataturk’s republic.”

“Our conclusion that between 1.5 and 2.5 million Christians were murdered, from 1894 to 1924, is a cautious estimate,” Morris says.