Palmerston and Africa brings British imperial history into vivid focus when the British Empire was at its most powerful, self-confident and serene, and when Palmerston was in his prime.

It concerns two British traders, Joseph Braithwaite and George Martin, whose trading station was destroyed by an act of 'piracy on land' by a Franco-Belgian naval force in 1849. In June 1850, Palmerston proclaimed his doctrine of 'Civis Romanus sum' in the Don Pacifico Affair in a triumphant speech in the House of Commons. He asserted the right to defend the citizen of the empire anywhere in the world and that 'the strong arm of England will protect him against injustice and wrong'.

Palmerston pursued the cause of Braithwaite and Martin with the same vigour despite the demands of high politics until frustrated by his 'dismissal' from office.

The Rio Nunez Affair shows Palmerston supporting 'legitimate trade' as opposed to the slave trade and recognising the importance of West Africa as a great international highway and centre of commerce. Commercial rivalry was growing among the European powers and here was a faint foreshadowing of the 'Scramble for Africa' and the practical limitations of imperial power even at its height.