icated by religious considerations and by the
excited state of European politics, almost precipitated a general war.
However, in November 1614 the dispute was temporarily settled by the
treaty of Xanten. Brandenburg obtained the duchy of Cleves with the
counties of Mark and Ravensberg, but as the Dutch and Spanish garrisons
were not withdrawn, these lands were only nominally under the elector's
rule. In 1609, John Sigismund had joined the Evangelical Union, probably
to win support in the Rhineland, and the same consideration was
doubtless one reason why, in 1613, he forsook the Lutheran doctrines of
his family, and became an adherent of the reformed, or Calvinist, faith.
This step aroused grave discontent in the electorate, and, quickly
abandoning his attempts to proselytize, the elector practically conceded
religious liberty to his subjects. Over the Cleves-Julich succession,
John Sigismund had incurred heavy expenses, and the public debt had
again mounted up. He was thus obliged to seek aid from the estates, and
in return for grants to make concessions to the nobles. The elector
spent much of his time in Prussia striving to assert his authority in
that duchy, and in August 1618, according to the arrangement of 1569,
became duke by the death of Albert Frederick. He only enjoyed this
dignity for a short time, as he died on the 23rd of December 1619. He
was succeeded by his eldest son, George William.

George William.

The new elector, born on the 3rd of November 1597, proved a weak and
incapable ruler. He had married Elizabeth, daughter of Frederick IV.,
elector palatine of the Rhine, and sister of the elector Frederick V.,
afterwards king of Bohemia, and before his accession had acted as his
father's representative in Cleves. Although a Protestant he was under
the influence of Adam, count of Schwarzenberg, who was a Roman Catholic
of imperialist sympathies. As a result the elector remained neutral
during the early years of the Thirty Years' War in spite of his
relationship with Frederick of the Palatinate, and the obvious danger to
his Rhenish lands. This attitude was not successful. Brandenburg was
ravaged impartially by both parties, and in 1627 George William attacked
his brother-in-law, Gustavus Adolphus of Sweden, who was using Prussia
as a base of operations for his war against Poland. This campaign was
short and inglorious for Brandenburg, and the elector was soon compelled
to make peace. Although alarmed b