A World of Art, in Washington

At the dawn of the 16th century, one of the most important national security documents in the world was a Portuguese map of the world, perhaps the most accurate map in all of Europe. It incorporated information from four series of voyages: Columbus to the Caribbean, Pedro Alvarez Cabral to Brazil, Vasco da Gama to eastern Africa and India, and the brothers Corte-Real to Greenland and Newfoundland. With the exception, all were Portuguese.

While the original 'Cantino Planisphere,' as the much-valued map was known, was lost on the Lisbon earthquake of 1755, a copy stolen by the Italians - I told you it was a national security document, did I not? - is now on display in Washington's own Sackler Gallery as part of an exhibit on the Portuguese empire. It explores ways in which Portuguese art and culture met with those of local craftsmen in Brazil, Africa, India, China and Japan; not only were foreign treasures such as ivory fans from Sri Lanka, tortoiseshell flasks from India and saltcellars from Sierra Leone taken back to Portugal, but the Portuguese were themselves depicted by the peoples they visited, and we find Portuguese motifs and themes incorporated into their work.

This two-way mirror on the Portuguese empire gives the exhibition its main thematic thread, showing that Europe's first naval empire connected civilisations for the first time through oceans that had hitherto divided humanity. Julian Raby, the Sackler's director, says the exhibition attempts to "catch that moment of wonder" as the world unfolded before the eyes of Europeans, and as the rest of the world encountered Europe, from the Benin kingdom of Nigeria to the shogunate of Japan.

And should you needed further reason to be fascinated by the Portuguese adventures, consider as the FT's review does that, "If Portugal was the first actor in a new age of globalisation, it was no mean feat for a country that, in the 15th century, had a population of only 1m."

'Encompassing the Globe: Portugal and the world in the 16th and 17th centuries' continues at the Sackler Gallery until September 16.