This Anglo-Russian pact of April 1805 formed the diplomatic core of the Third Coalition against Napoleonic France.
Key Facts
- Date signed
- 11 April 1805
- Original signatories
- Great Britain and the Russian Empire
- Austria joined
- 9 August 1805
- Sweden joined
- 3 October 1805
- Swedish troops financed
- 10,000 men
By the Numbers
Location
Cause → Event → Consequence
Growing concern among European powers over Napoleon's expanding French Empire and its satellite republics led Great Britain and Russia to seek a formal military alliance. Britain's ability to fund continental partners through subsidies made such coalitions viable, as demonstrated by its agreement to finance nearly all of Sweden's war costs.
On 11 April 1805, Great Britain and the Russian Empire signed the Treaty of Saint Petersburg, creating an offensive alliance explicitly directed against Napoleonic France. Austria acceded on 9 August 1805 and Sweden on 3 October 1805, broadening the coalition, while France remained allied with Spain and various satellite republics.
The treaty became one of the principal causes of the War of the Third Coalition, mobilising a multi-state military effort against Napoleon. Despite the coalition's formation, France and its allies ultimately prevailed in the ensuing campaign, reshaping the balance of power in Europe.
Political Outcome
Formation of an offensive anti-Napoleonic alliance that triggered the War of the Third Coalition
Britain and Russia acting without a formal alliance against France
Unified Third Coalition of Britain, Russia, Austria, and Sweden opposing Napoleonic France