y the edict of restitution of 1629,
George William took no steps to help the Protestants. In 1631, however,
Gustavus Adolphus marched on Berlin, compelled the elector to cede the
fortress of Spandau, and to aid him with men and money. The Brandenburg
troops then assisted the Swedes until after the death of Gustavus in
1632, and the Swedish defeat at Nordlingen in 1634, when the elector
assented to the treaty of Prague, which was made in May 1635 between the
emperor Ferdinand II. and John George I., elector of Saxony. The
imperialists did nothing, however, to drive the Swedes from Brandenburg,
and the unfortunate land was entirely at the mercy of the enemy. This
was the principal reason why the elector was unable to annex Pomerania
when its last duke, Bogislaus XIV., died in 1637. In 1638 George William
transferred his residence to Konigsberg, leaving Schwarzenberg to
administer the electorate. Although his harsh measures aroused some
irritation, the count did something to rid the land of the Swedes and to
mitigate its many evils; but its condition was still very deplorable
when George William died at Konigsberg on the 1st of December 1640,
leaving an only son, Frederick William. The most important facts in the
internal history of Brandenburg during the 16th century were the
increase in the power of the estates, owing chiefly to the continuous
pecuniary needs of the electors; the gradual decline in the political
importance of the towns, due mainly to intestine feuds; and the lapse of
the peasantry into servitude. These events gave a preponderance of power
to the nobles, but concurrently a number of circumstances were silently
preparing the way for a great increase of authority on the part of the
ruler. The substitution of the elector for the pope as head of the
church; the introduction of Roman law with its emphasis on a central
authority and a central administration; the determined and successful
efforts to avoid any partition of the electorate; and the increasing
tendency of the separate sections of the diet to act independently; all
tended in this direction. This new order was heralded in 1604 by the
establishment of a council of state, devoted to the interests of the
elector, which strengthened his authority, and paved the way for a
bureaucratic government.

Frederick William, the "Great Elector."

When Frederick William, the "Great Elector," became ruler of Brandenburg
in 1640 he found the country in a very dep