Portuguese participation in the slave trade 133This clearly shows that, with the exception of Great Britain, no country at
that time genuinely desired to take immediate or decisive steps.
But the slave trade as a method of recruiting manpower was doomed
in the medium or long term. The planters and slave-traders realized this—so
much so that the trade took on a spectacular new lease of life.
At the same time, Portugal's Atlantic Empire was undergoing profound
and irreversible changes. Since 1808 Portugal had been brought by Great
Britain to take a series of measures that were to impair her future relations
with Brazil. They entailed the opening to trade of all Brazilian ports, and the
ending of the rules reserving to Portugal the processing of colonial raw mat-
erials. Then, in 1810, Great Britain obtained 'most favoured Nation' treatment;
and finally, in 1811, all ports in Portuguese colonies were opened to trade. But
these liberalizing measures, which were particularly advantageous for Great
Britain, were also highly beneficial to Brazil : for the presence of the government
and the court at Rio de Janeiro, and the liberalization of the economy, gave
rise to an unprecedented development in the colony : administrative, political,
economic and cultural. In 1815, Brazil was elevated to the status of a kingdom,
and became aware of her national identity for the first time. Portugal, on the
other hand, was passing through a severe crisis, aggravated by the effects of a
ruinous war and invasion, and was still under occupation by the British army.
The mother country had become virtually a colony of her former colony, while
Portuguese Africa became daily more dependent on Brazil. In this situation
independence seemed inevitable, and it was consummated when the king
returned to Lisbon. Passed into law in 1822, it cut Portugal off from the
motive power of her economy. Once trade had been liberalized, Brazil no
longer needed the mother country : only Africa was essential to her, to keep
her plantations going. But, because of the slave trade, the development of the
Portuguese possessions in Africa had been completely neglected, thus reducing
Portugal's economic role to one of slave-trader. The prohibition of the trade
north of the Equator had benefited smuggling and the trade in the south.
Angola and the Congo were the main suppliers. Great Britain, however, tried
as far as possible to check infringements.
A supplementary convention to the treaty of 1815, signed in London in
1817, established the distinction between licit and illicit trading, while Portugal
and Great Britain agreed to a reciprocal right of search by their warships of
vessels flying their flags. Joint commissions were also set up to try prizes.
But, despite these measures—or perhaps because of them—the slave
trade flourished more than ever. It became clear that the only possible step
was absolute prohibition : this would make it possible to prosecute smugglers
who sheltered behind the Portuguese flag. Great Britain, faced with continual
changes of government in Portugal, had several times to break off negotiations.
Finally, on 10 December 1836, barely two months after coming to power,