John Ponsonby, 1st Viscount Ponsonby

On 28 February 1826, he went to Buenos Aires as envoy-extraordinary and minister-plenipotentiary until 1828, and moved then to Rio de Janeiro in the same capacity.

Once there he greatly fostered the independence of Uruguay as a buffer state between Argentina and Brazil, to the benefit of British commerce and overall peace.

Thus, as a diplomat, he was sent twice by the British Empire to promote the instauration of buffer states to protect its interests, Uruguay and Belgium, both of which survive to this very day, still deeply similar to their bigger neighbours.

Through Lord Grey, who had married his sister Mary Elizabeth, he had great influence, but his conduct as an ambassador sometimes caused official embarrassment, notably when he accompanied the emperor to Innsbruck in 1848.

[4] He was a keen diplomat of the "old school", a shrewd observer, and a man of large views and strong will.