By 1828 three competing customs unions had been established, comprising, collectively, the bulk of the states of the German Confederation, the most notable exception being the territories of the Austro-Hungarian Empire. Although theoretically equivalent, the Prussian-controlled northern union clearly dominated, and when it formed a commercial alliance with the southern union of Bavaria and Württemberg, a tipping point was reached. The Thuringian States led a breakaway from the Central union (1833) and shortly afterwards merged with the Prussians to form the Zollverein, or German customs union. As a defensive measure, the residual Central union, Hanover, Oldenburg and Brunswick, formed a Tax Union, which charged swingeing duties on Prussian goods passing through its territories. But Baden, Nassau, and Luxembourg joined the Zollverein, and, in 1844, Brunswick defected. In 1851–52 the last hold-outs, Hanover and Oldenburg, surrendered; Prussia then masterminded a series of further unification projects, including currency, weights and measures, infrastructure and postal services.
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