The Strangford Treaty was an 1810 treaty between the Portuguese colony of Brazil and the United Kingdom of Great Britain and Ireland. It provided major concessions to the British in the form of tariff reductions and other benefits.
In 1785, a decree proclaimed that Brazilian factories could only produce cloth that would be used for clothing slaves or to make sacks for food goods. This decree was lifted in 1808, accompanied by an open ports policy. To help recover their internal industry, Brazil imposed Tariff protection on imports.
During this period, the British had helped the Portuguese government to flee the invading Napoleonic army and find refuge in Rio de Janeiro. The Anglo-Irish diplomat, Percy Smythe, 6th Viscount Strangford, negotiated an agreement to grant Britain trade privileges with Brazil. In return for these Brazilian concessions, the British would convince the Portuguese government to recognise Brazilian independence.
The result of the treaty was that exports from the United Kingdom came to dominate the markets in Brazil. Imported British goods would only receive a 15% duty, compared to 25% for goods from other nations. It also limited Brazilian legal recourse against British subjects and allowed British agents to become established throughout the country. As a result, low cost imported goods manufactured by machine industry began to swamp the market that had previously been dominated by the local handicrafts industry. Exports of tobacco and sugar from Brazil were prohibited, which protected British producers in the West Indies.
The treaty was written so as to expire in 1825 unless renewed. It remained in effect until 1844.