I didn't know this: in 1794, the Corsican parliament voted for union with Great Britain, to be "a self-governing community under the sovereign authority of King George III. The Corsicans were granted their own flag, carrying a moor's head alongside the royal arms, as well as a motto: Amici e non di ventura, 'friends and not by chance'." The union lasted two years.

That Abulafia finds room for such an episode in a book of such ambitious scope shows how impressive his achievement is. To give you some idea: even though, perforce, historians attempting this kind of thing are obliged to give disproportionate space to recent history, we are still only starting on 1350 halfway through this book (pushing 800 pages, with notes).

And it is a wonderful idea for a book. The Mediterranean is a kind of traversable void that has been, for millennia, a space around which humans have been able to travel. It is both negative – you can't grow things on it, or build on it – and positive: you can use it to get to somewhere else, to take things there and bring other things back. Under "things" you may also include "ideas". I've sailed, over the years, round large stretches of it, and have everywhere been struck by the similarity of coastal cultures in every harbour and port I've seen. The religions and lifestyles of the inhabitants further inland may be different, but the pale blue of the fishing-boats; the eyes painted on the prows of the smaller vessels; the smell of frying sardines everywhere – these are constants, and I suspect that they have been so since antiquity.

That said, Abulafia warns us, in his conclusion, against searching for a "fundamental unity" of Mediterranean identity, and to "note diversity" instead. And there is indeed that, as the northern and western fringes of the sea guard themselves with increasing rigour against those wishing to move there from the southern fringes. The last picture in the book is of a small boatful of would-be African immigrants trying to land somewhere near Gibraltar. (And the plate above that shows a pullulating mass of humanity, not looking terribly diverse at all, sunbathing at Lloret de Mar in Catalonia, which I am old enough to remember as a quaint little resort.)

I had, at first, cocked an eyebrow at the book's subtitle – surely the word "human" is redundant? (I suppose a donkey's history of the Med could make for interesting, if unrelievedly grim, reading.) But it is full of stories that Abulafia has pulled from the flotsam and jetsam of history. Archaeologists sorting through the remains of an Etruscan settlement on the mouth of the Po found some artwork so bad that the anonymous pseudo-Attic artist has been given the name "the Worst Painter". The first Neanderthal bones were actually found much earlier than the ones in the Neander Valley; "Neanderthal Man" should really be called "Gibraltar Woman". Wenamum, an emissary from Karnak in Pharaonic Egypt, c1000BC, noted that the chief of Byblos, where he had gone to pick up timber, told him to "get out of my harbour!" every day for a month; but as he had kept other emissaries out for 17 years, he shouldn't complain. Herodotus tells us that Lydians invented board games (but not draughts) to keep their minds off hunger during a famine. A Christian request to Roger I, Norman count of Sicily in the 11th century, to move against the Tunisian port of Mahdia, was met by Roger lifting up his thigh and letting out "a great fart". The envoys of Dionysios the tyrant were mocked at the 384BC Olympic Games because he was – well, a tyrant (would that we had the balls to do the same today). The marble female head from Keros in the Cycladic islands, from the first half of the third millennium BC, is the most astonishingly beautiful piece of sculpture you will ever see, and makes every sculpture made afterwards seem redundantly and vulgarly over-detailed.

And so on. There is so much here that you risk brain overload. This is your must-take holiday read for the summer. Remember the cry of Xenophon's 10,000: "Thálatta! Thálatta!" – the sea, the sea!