ks from without as by divisions within, by the loss
of Bohemia and Hungary, by the loss of its hold over German Switzerland,
and still more by the mean and spiritless temper of its Imperial head,
Frederick the Third. But its ambition remained boundless as ever; and in
the Burgundian dominion, destined now to be the heritage of a girl, for
Mary was the Duke's only child, it saw the means of building up a
greatness such as it had never known. Its overtures at once turned the
Duke's ambition from France to Germany. He was ready to give his
daughter's hand to Frederick's son, Maximilian; but his price was that of
succession to the Imperial crown, and his election to the dignity of King
of the Romans. In such an event the Empire and his vast dominions would
pass together at his death to Maximilian, and the aim of the Austrian
House would be realized. It was to negotiate this marriage, a marriage
which in the end was destined to shape the political map of modern Europe,
that Duke and Emperor met in 1473 at Trier.

[Sidenote: Peace with France]

But if Frederick's policy was to strengthen his house the policy of the
princes of the Empire lay in keeping it weak; and their pressure was
backed by suspicions of the Duke's treachery, and of the possibility of a
later marriage whose male progeny might for ever exclude the house of
Austria from the Imperial throne. Frederick's sudden flight broke up the
conference; but Charles was far from relinquishing his plans. To win the
mastery of the whole Rhine valley was the first step in their realization,
and at the opening of 1474 he undertook the siege of Neuss, whose
reduction meant that of Koeln and of the central district which broke his
sway along it. But vast as were the new dreams of ambition which thus
opened before Charles, he had given no open sign of his change of purpose.
Lewis watched his progress on the Rhine almost as jealously as his
attitude on the Somme; and the friendship of England was still of the
highest value as a check on any attempt of France to interrupt his plans.
With this view the Duke maintained his relations with England and fed
Edward's hopes of a joint invasion. In the summer of 1474, on the eve of
his march upon the Rhine, he concluded a treaty for an attack on France
which was to open on his return after the capture of Neuss. Edward was to
recover Normandy and Aquitaine as well as his "kingdom of France";
Champagne and Bar were to be the prizes of Charl