avourable progress of the
negociation, an intercepted letter from the Elector to Pappenheim, the
imperial general in Westphalia, revealed the perfidy of that prince, as
having no other object in view by the whole negociation, than to gain
time for his measures of defence. Far from intending to fetter his
military operations by a truce with Sweden, the artful prince hastened
his preparations, and employed the leisure which his enemy afforded him,
in making the most active dispositions for resistance. The negociation
accordingly failed, and served only to increase the animosity of the
Bavarians and the Swedes.

Tilly's augmented force, with which he threatened to overrun Franconia,
urgently required the king's presence in that circle; but it was
necessary to expel previously the Spaniards from the Rhine, and to cut
off their means of invading Germany from the Netherlands. With this
view, Gustavus Adolphus had made an offer of neutrality to the Elector
of Treves, Philip von Zeltern, on condition that the fortress of
Hermanstein should be delivered up to him, and a free passage granted to
his troops through Coblentz. But unwillingly as the Elector had beheld
the Spaniards within his territories, he was still less disposed to
commit his estates to the suspicious protection of a heretic, and to
make the Swedish conqueror master of his destinies. Too weak to
maintain his independence between two such powerful competitors, he took
refuge in the protection of France. With his usual prudence, Richelieu
profited by the embarrassments of this prince to augment the power of
France, and to gain for her an important ally on the German frontier. A
numerous French army was despatched to protect the territory of Treves,
and a French garrison was received into Ehrenbreitstein. But the object
which had moved the Elector to this bold step was not completely gained,
for the offended pride of Gustavus Adolphus was not appeased till he had
obtained a free passage for his troops through Treves.

Pending these negociations with Treves and France, the king's generals
had entirely cleared the territory of Mentz of the Spanish garrisons,
and Gustavus himself completed the conquest of this district by the
capture of Kreutznach. To protect these conquests, the chancellor
Oxenstiern was left with a division of the army upon the Middle Rhine,
while the main body, under the king himself, began its march against the
enemy in Franconia.

The possession