The Treaty of Vossem was signed on 6 June 1673, between Frederick William, Elector Brandenburg and Louis XIV of France; England, then a French ally against the Dutch, was included as a party to the terms but not a signatory.

He also faced a threat from Sweden, with whom he disputed ownership of lands in Pomerania; the French paid them subsidies to remain neutral but promised military support against Brandenburg 'if needed'.

At the same time, Emperor Leopold was dealing with a French-backed revolt in Hungary and suspected Brandenburg-Prussia of seeking to drag him into war on behalf of their Dutch Calvinist co-religionists.

[4] The treaty tied Frederick William to Imperial strategy and Leopold viewed preventing French gains in the Rhineland as a higher priority than helping the Dutch.

Mutual suspicions meant Frederick William did not enter the alliance until July 1674; despite taking most of Pomerania during the Scanian War, he was isolated and forced to return most of his conquests at Saint-Germain-en-Laye in 1679.