VIENNA, Austria -- Turkey is today considered a rising power in the Middle East and Europe. But just a few centuries ago, the Turks ruled large chunks of both regions under the banner of the Ottoman Empire. Turkish-led forces drove deep into Europe, even reaching the gates of Vienna twice before being defeated. Now they're back. Thanks to heavy immigration over the past four decades, at least a half a million Turks now live in Austria, with many settling in Vienna. When you think of the cradles of Judeo-Christian, Western civilization, Vienna is certainly at the top of the list. But some residents say this city is changing--and becoming increasingly influenced by Islam. "They are here to dominate," said Vienna-based counter-jihad acticist Harald Fiegel. "And of course, knowing a little bit about Islam, you can read it there. They are are here to dominate all the world, not just Europe." Fiegel monitors Islamic growth in Austria. He says Turkish Muslim immigrants are not assimilating. "What they are trying to do is segregation," he told CBN News. "To maintain Turkish national and religious identity." There may be a larger hand behind that strategy. The Turkish government is home to a religous affairs office called "Diyanet" that approves imams and mosque-building inside Turkey. Turkish officials say Diyanet has a "global vision." It's influence on Turkish immigrant communities across Europe is growing. In Austria, Diyanet has established a Austrian/Turkish cultural ...