Last Summer I was briefly in Ponte da Barca, a small town in the valley of the river Lima, so far to the north of Portugal it is almost in Spain. Old buildings line the main street, and the great house and parish church stand apart on a small hill, within a stone's throw of which are the bridge and the pillory. It is one of those places - Winchelsea in southern England is another - which seems lost in time. Yet this unpretentious town is reputedly the native place of Fernão de Magalhães, better known as Magellan, the first circumnavigator of the world.

This curious contrast between the intensely parochial and the heroically far- flung runs right through the six hundred years of Portugal's engagement with the world. (Portuguese and English are still the only languages in which one might plausibly conduct a world journey.) The seventeenth-century Jesuit preacher and politician Father Antonio Vieira, who spent much of his life on wearisome missions between Portugal and Brazil, put it poetically: 'God h as given the Portuguese a small country as their cradle and the whole world as their grave.' Malyn Newitt, in this survey of the first two – and – a – half centuries of Portugal's expansion, gives the same judgement a sting in the tail: 'The extraordinary enterprise and spirit of adventure that took individual Portuguese to every corner of the globe to make their fortunes is in marked contrast to the stagnation and the total lack of enterprise that they showed at home.'

Newitt's explanation for this strange paradox, and for the early genesis (in the fifteenth century) of Portuguese expansion, is broadly this: Portugal was so poor and backward a country that its people were literally forced to emigrate. Crucial to their expansion were Italian (particularly Genoese) technical and commercial skills, which