In front of Prague, he sent for Chevert, lieutenant-colonel of the regiment of Beauce, of humble origin, but destined to rise by his courage and merit to the highest rank in the army; the two officers made a reconnoissance; the moment and the point of attack were chosen.

At the approach of night on the 25th of November, 1741, Chevert called up a grenadier.

"Thou seest yonder sentry ?" said he to the soldier.

"Yes, colonel." "He will shout to thee, 'Who goes there ?'" "Yes, colonel." "He will fire upon thee and miss thee." "Yes, colonel." "Thou'lt kill him, and I shall be at thy heels." The grenadier salutes, and mounts up to the assault; the body of the sentry had scarcely begun to roll over the rampart when Colonel Chevert followed the soldier; the eldest son of Marshal Broglie was behind him.
Fifty men had escaladed the wall before the alarm spread through the town; a gate was soon burst to permit the entrance of Count Maurice with a body of cavalry.

Next day the elector was crowned as King of Bohemia; on the 13th of January, 1742, he was proclaimed emperor, under the name of Charles VII.
A few weeks had sufficed to crown the success; less time sufficed to undo it.