The main focus of the passage is ......... .

After the death of Ptolemy, the father of modern
geography, Christianity conquered the Roman
Empire and most of Europe. Then we observe a
Europe-wide phenomenon of scholarly amnesia,
which dominated the continent from A.D. 300 to at
least 1300. During those centuries, Christian faith
and dogma suppressed the useful image of the
world that had been so slowly, so painfully and so
scrupulously drawn by ancient geographers. We no
longer find Ptolemy's careful outlines of shores,
rivers and mountains, handily overlaid by a grid
constructed of the best-known astronomical data.
Instead, simple diagrams authoritatively declare the
shape of the true world, though they are only
religious caricatures.