It's not a stretch, it's historical.
When the crusades started in 1099, Muslim armies had killed thousands of Christians in the Levant, the Middle East, Spain, Portugal, France and Italy.
Muslims had controlled Spain and Portugal for 400 years at that point. They forced Christians living under their rule to pay the tax known as the "jizya" or Christians were forced to convert to Islam under threat of death.
ISIS did the same thing in 2014-2015 when they established the caliphate in Syria and Iraq.
Christians flee the Iraqi city of Mosul after Islamist militants threatened to kill them unless they converted to Islam or paid a "protection tax".
www.google.com