Formalized the British-Prussian wartime alliance with an annual gold subsidy of £670,000, the largest Britain had ever paid an ally.
Key Facts
- Date signed
- 11 April 1758
- Annual subsidy to Prussia
- £670,000 GBP per year
- Alliance dissolved
- 30 April 1762
- Dissolved by
- John Stuart, 3rd Earl of Bute
- British garrison commitment
- Port of Emden, first Continental troop deployment
By the Numbers
Cause → Event → Consequence
The Convention of Westminster (1756) had created an informal alignment between Britain and Prussia as both faced the shifting alliances of the Seven Years' War. Britain needed Prussia to defend Hanover and adjacent territories on the Continent, while Prussia required financial support to sustain its campaigns against France, Austria, and Russia.
On 11 April 1758, Britain and Prussia signed the Anglo-Prussian Convention, formalizing their alliance. Britain pledged an annual subsidy of £670,000 in gold—the largest wartime subsidy it had ever granted an ally—and agreed to garrison Emden. In return, Prussia was expected to contribute forces to the German Army of Observation under Ferdinand of Brunswick.
The alliance held for several years and underpinned British and Prussian strategy in the Seven Years' War. However, it dissolved acrimoniously on 30 April 1762 when the Earl of Bute, backed by George III, ended it over the objections of Newcastle and Pitt, straining Anglo-Prussian relations at a critical stage of the conflict.
Political Outcome
A formal alliance was concluded; Britain committed an unprecedented annual gold subsidy and a Continental garrison in exchange for Prussian military cooperation defending Hanover.
Informal alignment since the Convention of Westminster (1756) with no binding commitments or subsidy
Formal treaty with binding no-separate-peace clause and the largest British wartime subsidy ever paid to an ally