Alliance between the Commonwealth of Poland and Prussia (Warsaw, Polish-Lithuanian Commonwealth; 1790)
A mutual defense pact between Poland-Lithuania and Prussia that ultimately failed to prevent Prussian participation in the partitions of Poland.
Key Facts
- Date signed
- 29 March 1790
- Parties
- Polish-Lithuanian Commonwealth and Kingdom of Prussia
- Alliance type
- Mutual defense
- Russia invaded Commonwealth
- May 1792
- Prussia's cited reason for refusal
- Not consulted on the 3 May Constitution
- Prussia joined partition
- 1793, aided Russia against Kościuszko Uprising
By the Numbers
Location
Cause → Event → Consequence
In 1790, Prussia sought allies against Austria or Russia, while the Polish-Lithuanian Commonwealth sought assurances from a powerful neighbor that it could pursue internal governmental reforms without foreign military intervention. Both states thus had short-term strategic reasons to formalize a mutual defense arrangement.
On 29 March 1790, representatives of the Polish-Lithuanian Commonwealth and the Kingdom of Prussia signed a mutual defense alliance in Warsaw. The treaty was intended to protect the Commonwealth as it embarked on major reforms, including the eventual adoption of the 3 May Constitution, under the assumption that Prussian backing would deter hostile intervention.
The alliance proved illusory. Prussia grew alarmed by the Commonwealth's internal reforms, which it viewed as threatening. When Russia invaded in May 1792, Prussia refused to honor the treaty, citing the unreformed 3 May Constitution as a pretext. By 1793, Prussia had reversed course entirely, actively assisting Russia in suppressing the Kościuszko Uprising and partitioning the Commonwealth.
Political Outcome
The alliance failed; Prussia refused to intervene when Russia invaded the Commonwealth in 1792 and subsequently aided the 1793 partition.
Commonwealth seeking reform guarantees; Prussia seeking a counterweight to Austria or Russia
Alliance defunct; Prussia joined Russia in partitioning the Commonwealth by 1793