In 1085, Moorish Toledo was conquered by Alfonso VI.
According to prof. Robert Sapolsky (he is a primatologist and neurobiologist, but usually all information he gives is very reliable), at the time of the conquest there was more cumulative information in the library of Toledo than in the whole Christendom, especially when it comes to philosophy and science. Could this be correct? How did repositories of knowledge (libraries) in Christian Europe compared with the Toledo library in number of volumes, reputation of authors, breadth and depth of topics covered, or other measures? In particular, how about the Byzantine libraries following the Carolingian Renaissance?
The answer has to contain some objective measure to fit the format of this forum, it could be e.g. the number of prominent antique/Arab philosophers whose works were known in Christian Europe before the conquest vs the books in the library, or some very significant works that were available in the library but not known in Christian Europe at the time, or any other objective measure that is available.
This is indirectly confirmed by the existence of Toledo School of Translators, but I could not find any quantitative references.