The pretext was that it was necessary to restore order in the anarchic Polish-Lithuanian Commonwealth. The real reason was the avarice of three imperialistic, absolute states whose political systems completely contradicted the Polish traditions of democracy, civil liberty, and self-government.
The roots of the collapse of the Polish-Lithuanian Commonwealth go back to the Wasa Era in the 17th Century when Poland was overrun during the Swedish Deluge (1655-1660). Poles were slow to recover from the destruction of thousands of churches, schools, and civic buildings. The 'liberum veto", first used 1669, became a device to stymie any legislation that was passed by the Sejm to reform or change the Commonwealth. In 1730, the empires of Prussia, Russia, and Austria signed a secret ptotocol known as Lowenwolde's Treaty which sought to maintain the status quo by ensuring that the Commonwealth's laws did not change. And a few strategically placed bribes brought efforts to reform or change the Commonwealth to a standstill.
The Polish-Lithuanian Commonwealth was clearly on the path of becoming a mere vassal state of Czarist Russia. King Stanislaw Poniatowski was a lover of Czarina Catherine the Great and the Russian ambassador, Nicholas Repnin, dictated the terms of a new constitution to the Sejm in 1767. Many of the detractors or objectors to this new constitution were exiled to Kaluga in Russia by orders of Nicholas Repnin.
The patriotic Bar Confederation was formed to expel Russian influences and forces from the realm. But the civil war of 1768-1772 which resulted from the Bar Confederation's efforts to maintain the integrity and independence of the Commonwealth instead provided the three imperialistic powers with an excuse to seize territory from the Commonwealth - restoring order in a land where anarchy reigned. And Poles were soon to become a nation without a country.
Emperor Frederick the Great of Prussia long had ambitions on Polish lands along the Baltic coast and the linking by land of East Purussia and the Margraviate of Brandenburg. After Catherine the Great's armies scored a series of successes against the Ottoman Turks along the Danube, Austria's Empress Maria Theresa became quite alarmed and considered military action. Frederick came up with a scheme which would satisfy his territorial ambitions, redirect Catherine's territorial aims, and defuse Maria Theresa's alarm. It was accomplished totally at the expense of the exhausted Polish-Lithuanian Commonwealth. The partition treaty was ratified by the three signatories in September, 1772 and the First Partition of Poland became a reality.
Most Poles sensed that their fate was in the hands of their three imperialistic neighbors unless steps were taken immediately to reform their government. But, alas, conditions in Poland continued to deteriorate. Finally, in a moment of utmost bravery and brilliance, the Polish Sejm adopted the Constitution of 3 May in 1791. This comnstitution, the first of its kind in Europe, enfranchised the comman man, established the separation of powers among the three branches of government, and eliminated the abuses of The "Repnin Sejm". When this civic regeneration was sensed by their neighbors, a Russian army invaded Poland in 1792 followed, in turn, by the Prussian armies. In 1793, a second Parition of Poland was arrived at, this time without the participation of Empress Maria Theresa.
Although, in 1794, Thadeusz Kosciuszko distinguished himself in resisting the Second Partition of Poland and forced revocation of the Constitution of 3 May, he and his men would not long withstand the onslaught of the Czarist armies. Russia, Prussia, and Austria found that the ultimate solution of their "Polish problem" was to simply erase the Polish-Lithuanian Commonwealth from the maps of Europe. Their representatives signed the treaty on 24 October 1795 which divided the territories of the Commonwealth between them. The Third Partition of Poland was completed.
Poles became a nation without a country.