Boris Johnson stated in a 2007 essay that "the first printing press was not seen in Istanbul until the middle of the nineteenth century". Is this true?  “It is extraordinary to think that under the Roman/Byzantine empire, the city of Constantinople kept the candle of learning alight for a thousand years, and that under Ottoman rule, the first printing press was not seen in Istanbul until the middle of the nineteenth century. Something caused them to be literally centuries behind.” A quote from a Boris Johnson essay from 2007. I am wondering, is this actually true, and if so, what were the reasons behind it?