No such thing as the "dark ages"
The mythology of one-way technology transfer from the arab world to the west is just that: a myth. There was a great deal of technological and cultural exchange in both directions (though many inventions claimed as arab are actually chinese and indian) and the contemporary west was nothing like the backwards, illiterate backwater of popular myth.
What there was, however, was a certain amount of... shall we say, rent seeking? A few Arab kings sat smack on the major trade routes to the orient and India and were keen to make sure they made a nice profit, whilst expanding the borders of the islamic world. The first crusade, though it ended badly (understatement of the year I suppose), was an attempt to push back an invasion of several eastern christian kingdoms and also protect those trade routes. The later great age of exploration was an attempt to bypass the now entrenched arab and muslim rulers, who extracted a healthy profit from trade between east and west.
Point being, there was trade in both directions, and technological exchange in both directions, so please drop this whole "dark ages" rubbish. It's no less propaganda than the idea that "arabs stole everything".