Man’s first instinct has always been to return to the sea

Travelling the Indus valley late in the third millennium BC you would have been awed by two Bronze Age megacities, 320 miles apart, ‘massive and tightly planned, very similar in layout’, their bricks and measures standardised, evidence of rigid authority. Their trade goods included Afghan lapis lazuli, Omani vases, legal seals from Sumeria, carnelian beads, packed for dispatch to Sumer — and that is almost all that is left of Harappa and Mohenjo-daro, and more than we know of them.

Their names are modern labels. This section of The Boundless Sea, David Abulafia’s fascinating ‘human history of the oceans’, is one of many moments of thrilling implication. (Do not assume anyone will know the name of London in 5,000 years’ time.) Pirates and sea battles, navigators, cartographers and many resonant characters illumine his elegant pages; but what emerges is an engrossing history of seaborne trade and discovery, the threading together of
the globe.

Humanity appears here less like a species than a single organism, making its way from land to land, fleeing war or environmental change, or prospering by trade and allegiance. The progress of mankind is marked in ceramic shards, such as those Omani vases; in inscriptions on stone, such as the ones left by Portuguese navigators in southern Africa; in records of discovery, such as the Periplous of the early Greek navigators; and in story, such as the one about the giant octopus which Polynesian seafarers were pursuing when they discovered New Zealand.

The Boundless Sea is a work of immense scholarship, a forensic tribute to human enterprise. Did you know that Greco-Roman navigators ventured as far as Malaya? That standards of living in Roman Carthage and Alexandria were ‘perhaps higher than at any time before the 18th century’? That south of Yemen, on the island of Socotra, there is a cave beloved of seafarers who, between the 1st century BC and the 6th century AD, left inscriptions in languages including Sanskrit, Greek, Indian, Persian, Ethiopic and South Arabian, allowing us to trace some of their networks? ‘A historian ignores the smaller, apparently insignificant places at his or her peril,’ Abulafia notes.