In 1640, Frederick William, known as the great Elector, succeeded his father.

He it was who laid the foundations for that system of government by which a small German principality has grown to be the most powerful military monarchy in modern Europe.

He held his own against the Emperor; he fought with the Poles and compelled their King to grant him East Prussia; he drove the Swedes out of the land.

More than this, he enforced order in his own dominions; he laid the foundation for the prosperity of Berlin; he organised the administration and got together a small but efficient military force.

The growing power of the Elector was gained to a great extent at the expense of the nobles; he took from them many of the privileges they had before enjoyed.