On the outbreak of the religious war of 1618 he raised a regiment of Cuirassiers, and fought at its head.

Two years later he was made quartermaster general of the army, and marched at the head of an independent force into Moravia, and there re-established the Imperial authority.
"The next year he bought from the Emperor Ferdinand, for a little over 7,000,000 florins, sixty properties which the emperor had confiscated from Protestants whom he had either executed or banished.

He had been made a count at the time of his second marriage; he was now named a prince, which title was changed into that of the Duke of Friedland.

They say that his wealth is so vast that he obtains two millions and a half sterling a year from his various estates.
"When in 1625 King Christian of Denmark joined in the war against the emperor, Wallenstein raised at his own cost an army of 50,000 men and defeated Mansfeldt's army.

After that he cleared the Danes out of Silesia, conquered Brandenburg and Mecklenburg, and laid siege to Stralsund, and there broke his teeth against our Scottish pikes.