The arrangement was supposed to refer to the previous conventions between those two crowns, with the Republic, and the Protestant princes and powers.

Count Zollern, whom we have seen bearing himself so arrogantly as envoy from the Emperor Rudolph to Henry IV., was now despatched by Matthias on as fruitless a mission to the congress at Xanten, and did his best to prevent the signature of the treaty, except with full concurrence of the Imperial government.

He likewise renewed the frivolous proposition that the Emperor should hold all the provinces in sequestration until the question of rightful sovereignty should be decided.

The "proud and haggard" ambassador was not more successful in this than in the diplomatic task previously entrusted to him, and he then went to Brussels, there to renew his remonstrances, menaces, and intrigues.
For the treaty thus elaborately constructed, and in appearance a triumphant settlement of questions so complicated and so burning as to threaten to set Christendom at any moment in a blaze, was destined to an impotent and most unsatisfactory conclusion.
The signatures were more easily obtained than the ratifications.
Execution was surrounded with insurmountable difficulties which in negotiation had been lightly skipped over at the stroke of a pen.

At the very first step, that of military evacuation, there was a stumble.
Maurice and Spinola were expected to withdraw their forces, and to undertake to bring in no troops in the future, and to make no invasion of the disputed territory.
But Spinola construed this undertaking as absolute; the Prince as only binding in consequence of, with reference to, and for the duration of; the Treaty of Xanten.