In founding and expanding their colonial empire, the English and then the British moved millions of people over thousands of miles. Mass migration was the sine qua non of empire-building, for without the human means of controlling and exploiting conquered land, the land itself was useless. This was why the Royal Navy carried sailors and soldiers to ports and garrisons the world over, and it was why, until 1808, British merchants enslaved and then trafficked Africans from the Guinea coast to work on the plantations of the American colonies and the Caribbean.

Yet, as the Australian historian Graham Seal explains, there was a third major group of migrants, almost always unwilling participants in the colonial mission, whose blood and sweat fertilised the ground of Georgia, Guyana and New South Wales. These transported men, women and children are the ‘condemned’ of Seal’s title – the convicts, abductees, political rebels and plain unlucky souls who peopled the empire.

Transportation – in the popular imagination, at least – attaches primarily to the penal colonies of Australia. But, as Seal sets out, it had been an important policy since the 16th century, when the colonial enthusiast Richard Hakluyt urged Elizabeth I to endorse a programme of removing ‘the fry of wandering beggars of England that grow up idly’ to the distant parts of the world, where they might prove more useful, not only as workers but also as consumers who would provoke an ‘utteraunce of the