Thus, then, all the advantages lay with the relieving army.
Several officers in disguise were despatched, by Daun, to carry into Prague the news of his advance; and to warn Prince Karl to sally out, with the whole of his force, and fall upon the Prussians as soon as he attacked them in the rear.

So vigilant, however, were the besiegers that none of these messengers succeeded in entering Prague.
On the 13th Frederick set out, with 10,000 men--to be followed by 4000 more under Prince Maurice, two days later, these being all that could be spared from the siege works--to join Bevern, who had fallen back as Daun advanced.

The junction effected, Frederick joined Bevern and approached Daun, who was posted in a strong position near Kolin, thirty-five miles from Prague.

On the 17th Prince Maurice arrived, and after several changes of position the armies faced each other on the 18th, within a short distance of Kolin.
Daun's new position was also a strong one, and was, in fact, only to be assailed on its right; and the Prussian army was moved in that direction, their order being to pay no attention to the Austrian batteries or musketry fire, but to march steadily to the spot indicated.

This was done.