Question: What dissolved the privileges in Poland of the empire that the British sided with against the Ottomans, the Kingdom that acquired some Thuringian territory in 1815, and the Habsburg Monarchy?

Knowledge 1: Thuringia
Some reordering of the Thuringian states occurred during the German Mediatisation from 1795 to 1814, and the territory was included within the Napoleonic Confederation of the Rhine organized in 1806. The 1815 Congress of Vienna confirmed these changes and the Thuringian states' inclusion in the German Confederation; the Kingdom of Prussia also acquired some Thuringian territory and administered it within the Province of Saxony. The Thuringian duchies which became part of the German Empire in 1871 during the Prussian-led unification of Germany were Saxe-Weimar-Eisenach, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg-Gotha, Schwarzburg-Sondershausen, Schwarzburg-Rudolstadt and the two principalities of Reuss Elder Line and Reuss Younger Line. In 1920, after World War I, these small states merged into one state, called Thuringia; only Saxe-Coburg voted to join Bavaria instead. Weimar became the new capital of Thuringia. The coat of arms of this new state was simpler than they had been previously. [SEP] Knowledge 2: Near East
If the British Empire was now going to side with the Russian Empire, the Ottoman Empire had no choice but to cultivate a relationship with the Austro-Hungarian Empire, which was supported by the German Empire. In a few years these alignments became the Triple Entente and the Triple Alliance (already formed in 1882), which were in part a cause of World War I. By its end in 1918 three empires were gone, a fourth was about to fall to revolution, and two more, the British and French, were forced to yield in revolutions started under the aegis of their own ideologies. [SEP] Knowledge 3: Szlachta
During the Partitions of Poland from 1772 to 1795, its members began to lose these legal privileges and social status. From that point until 1918, the legal status of the nobility was essentially dependent upon the policies of the three partitioning powers: the Russian Empire, the Kingdom of Prussia, and the Habsburg Monarchy. The legal privileges of the szlachta were legally abolished in the Second Polish Republic by the March Constitution of 1921.
Knowledge 1: Thuringia
Some reordering of the Thuringian states occurred during the German Mediatisation from 1795 to 1814, and the territory was included within the Napoleonic Confederation of the Rhine organized in 1806. The 1815 Congress of Vienna confirmed these changes and the Thuringian states' inclusion in the German Confederation; the Kingdom of Prussia also acquired some Thuringian territory and administered it within the Province of Saxony. The Thuringian duchies which became part of the German Empire in 1871 during the Prussian-led unification of Germany were Saxe-Weimar-Eisenach, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg-Gotha, Schwarzburg-Sondershausen, Schwarzburg-Rudolstadt and the two principalities of Reuss Elder Line and Reuss Younger Line. In 1920, after World War I, these small states merged into one state, called Thuringia; only Saxe-Coburg voted to join Bavaria instead. Weimar became the new capital of Thuringia. The coat of arms of this new state was simpler than they had been previously. [SEP] Knowledge 2: Near East
If the British Empire was now going to side with the Russian Empire, the Ottoman Empire had no choice but to cultivate a relationship with the Austro-Hungarian Empire, which was supported by the German Empire. In a few years these alignments became the Triple Entente and the Triple Alliance (already formed in 1882), which were in part a cause of World War I. By its end in 1918 three empires were gone, a fourth was about to fall to revolution, and two more, the British and French, were forced to yield in revolutions started under the aegis of their own ideologies. [SEP] Knowledge 3: Szlachta
The sovereignty of szlachta was ended in 1795 by Partitions of Poland, and until 1918 their legal status was dependent on policies of the Russian Empire, the Kingdom of Prussia or the Habsburg Monarchy.
Knowledge 1: Thuringia
Some reordering of the Thuringian states occurred during the German Mediatisation from 1795 to 1814, and the territory was included within the Napoleonic Confederation of the Rhine organized in 1806. The 1815 Congress of Vienna confirmed these changes and the Thuringian states' inclusion in the German Confederation; the Kingdom of Prussia also acquired some Thuringian territory and administered it within the Province of Saxony. The Thuringian duchies which became part of the German Empire in 1871 during the Prussian-led unification of Germany were Saxe-Weimar-Eisenach, Saxe-Meiningen, Saxe-Altenburg, Saxe-Coburg-Gotha, Schwarzburg-Sondershausen, Schwarzburg-Rudolstadt and the two principalities of Reuss Elder Line and Reuss Younger Line. In 1920, after World War I, these small states merged into one state, called Thuringia; only Saxe-Coburg voted to join Bavaria instead. Weimar became the new capital of Thuringia. The coat of arms of this new state was simpler than they had been previously. [SEP] Knowledge 2: Near East
If the British Empire was now going to side with the Russian Empire, the Ottoman Empire had no choice but to cultivate a relationship with the Austro-Hungarian Empire, which was supported by the German Empire. In a few years these alignments became the Triple Entente and the Triple Alliance (already formed in 1882), which were in part a cause of World War I. By its end in 1918 three empires were gone, a fourth was about to fall to revolution, and two more, the British and French, were forced to yield in revolutions started under the aegis of their own ideologies. [SEP] Knowledge 3: Powder keg of Europe
The powder keg of Europe or Balkan powder keg was the Balkans in the early part of the 20th century preceding World War I. There were a number of overlapping claims to territories and spheres of influence between the major European powers such as the Russian Empire, the Austro - Hungarian Empire, the German Empire and, to a lesser degree, the Ottoman Empire, the United Kingdom and Kingdom of Italy.

Answer: March Constitution of Poland