Treaty of Bromberg - Impact and Assessment

Impact and Assessment

For the House of Hohenzollern, Wehlau-Bromberg was a "major geopolitical gain and surge in wealth and prestige", while Poland had "substantially benefited" from Brandenburgian support during the war. According to Robert I. Frost, the concessions Poland made in Wehlau and Bromberg were thought as tactical and open to later reversal - which however did not happen due to the internal weakness of the commonwealth. Christopher M. Clark says that John Casimir of Poland was on the one hand "eager to separate Brandenburg from Sweden and to neutralize it as a military threat" when Poland-Lithuania was threatened by the Tsardom of Russia, and on the other hand was ready to accept the Hohenzollerns' demands due to pressure by the House of Habsburg, who after the emperor's incidental death earlier that year needed to secure the elector's vote, and whose "urgings carried a considerable weight, since the Poles were counting on Austrian assistance in the event of a renewed Swedish or Russian attack." Clark thus views Frederick William as a "beneficiary of international developments beyond his control," and verifies his thesis by the post-Bromberg developments, where the elector lost all further war gains due to French intervention at the Treaty of Oliva.

Józef Włodarski regards the treaty as one of the heaviest mistakes in Polish foreign policy towards Prussia with fatal consequences for Poland. According to Anna Kamińska, the treaty marked the point when Poland's influence on the Baltic was lost and Poland-Lithuania's position in Europe declined. Frost says that the treaty was subject to criticism of historians such as Kazimierz Piwarski, who says that the prize paid by Poland in Bromberg was unnecessarily high. According to Frost, these critics argue from a post-partition point of view, and neglect the complexity of the contemporary situation: "Contemporary politicians were aware of the dangers of conceding sovereignty, which they accepted not because they were stupid, indifferent, or lacking in foresight, but because the alternatives seemed more damaging to the Commonwealth's interests", he says. While Frost regards Piwarski's assertion, that the Polish decision was heavily influenced by the Habsburgs, to have merit, he also says that the Polish interest in a rapprochment with Brandenburg had already emerged in 1656, long before Lisola entered the scene.