The 1657 Treaty of Vienna committed Habsburg emperor Leopold I to deploy 12,000 troops in support of Poland–Lithuania against Sweden and Brandenburg during the Second Northern War.
Key Facts
- Date concluded
- 27 May 1657
- Habsburg troops promised
- 12,000 troops
- Prior treaty troop commitment
- 4,000 troops
- Troops crossed Polish border
- June 1657
- Maintenance cost borne by
- Poland–Lithuania
By the Numbers
Location
Cause → Event → Consequence
Ferdinand III had previously committed only 4,000 troops to Poland–Lithuania under the 1656 Treaty of Vienna, an arrangement deemed ineffective. His death in April 1657 created an opening to renegotiate terms with his successor, Leopold I, who sought a stronger posture against the Swedish-Brandenburgian alliance threatening Polish territory.
On 27 May 1657, Leopold I and John II Casimir concluded a new Treaty of Vienna, formalizing an Austro–Polish alliance. Leopold pledged 12,000 Habsburg troops to assist Poland–Lithuania in the Second Northern War, with the significant condition that Poland would bear the cost of maintaining these forces.
The Habsburg troops crossed into Poland in June 1657, substantially reinforcing the Polish war effort against Sweden and Brandenburg. The treaty marked a meaningful escalation of Austrian involvement in the Second Northern War and shifted the military balance by tripling the previously promised troop commitment.
Political Outcome
Austria committed 12,000 troops to Poland–Lithuania, forming an alliance against the Swedish-Brandenburgian alliance in the Second Northern War.
Limited Habsburg support of 4,000 troops under the ineffective 1656 treaty; Sweden and Brandenburg held initiative
Strengthened Austro–Polish alliance with 12,000 Habsburg troops deployed, increasing pressure on the Swedish-Brandenburgian side