In a letter to Peel on 18 October 1844, Lord Aberdeen forecast that Britain's relations with Brazil would soon become ‘unpleasant and complicated’. Partly as a demonstration of her independence from Britain, Brazil had insisted—as she had the right to do—on terminating the Anglo-Brazilian commercial treaty of 1827, one of the two treaties which had been imposed upon her more than fifteen years earlier as the price of British recognition of her independence from Portugal. The other treaty, the Anglo-Brazilian abolition treaty of 1826, was of indefinite duration and could not therefore be terminated unilaterally by Brazil. However, the treaty of 1817, which formed part of the treaty of 1826—and a crucial part, since it was under this treaty that the British navy exercised the right of search and the Anglo-Brazilian mixed commissions adjudicated upon captured Brazilian vessels—was not permanent. Indeed, it would have been brought to an end as early as March 1830 when the Brazilian slave trade first became entirely illegal had not Lord Palmerston taken advantage of the separate article of 11 September 1817 which permitted it to continue in force for a further fifteen years.