itio Achillea_, bequeathed the new mark to one of his younger
sons. He died on the 8th of January 1598.

Joachim Frederick.

Joachim Frederick, who now became elector, was born on the 27th of
January 1546. Since 1553 he had held the bishopric of Havelberg, since
1555 that of Lebus; he had been administrator of Magdeburg since 1566,
and of Brandenburg since 1571. Resigning these dignities in 1598, he
contested his father's will, and was successful in preventing a
division of the electorate. An agreement with George Frederick, the
childless margrave of Ansbach and Bayreuth, paved the way for an
arrangement with the elector's younger brothers, who after the
margrave's death in April 1603, shared his lands in Franconia, and were
compensated in other ways for surrendering all claims on Brandenburg.
This agreement, known as the Gera Bond, ratified the _Dispositio
Achillea_. By George Frederick's death, Joachim became administrator of
the duchy of Prussia, ruled nominally by the weak-minded Albert
Frederick, but he had some difficulty in asserting his position. In
Brandenburg he made concessions to the nobles at the expense of the
peasantry, and admitted the right of the estates to control taxation. In
religious matters he was convinced of the necessity of a union between
Lutherans and Calvinists, and took steps to bring this about. Public
opinion, however, in Brandenburg was too strong for him, and he was
compelled to fall back upon the Lutheran _Formula_ and the religious
policy of his father. Joachim seems to have been a wise ruler, who
improved in various ways the condition of the mark. He married
Catherine, daughter of John, margrave of Brandenburg-Custrin, and when
he died, on the 18th of July 1608, was succeeded by his eldest son John
Sigismund.

John Sigismund.

The new elector, born on the 8th of November 1572, had married in 1594
Anna, daughter of Albert Frederick of Prussia, a union which not only
strengthened the pretensions of the electors of Brandenburg to the
succession in that duchy, but gave to John Sigismund a claim on the
duchies of Cleves, Julich and Berg, and other Rhenish lands should the
ruling family become extinct. In March 1609 the death of Duke John
William left these duchies without a ruler, and by arrangement they were
occupied jointly by the elector and by his principal rival, Wolfgang,
son of Philip Louis, count palatine of Neuburg. This proceeding aroused
some opposition, and, compl