Christian Europe was trembling before them.

And now an army of three hundred thousand had crossed the Danube, sweeping all opposition before them, and were spreading terror and destruction through Hungary.

The capture of that immense kingdom seemed to leave all Europe defenseless.
The emperor and his Catholic friends were fearfully alarmed.

Here was a danger more to be dreaded than even the doctrines of Luther.

All the energies of Christendom were requisite to repel this invasion.