Charting the human story through how we drew our maps

On December 7, 1972, one of the three astronauts on board the Apollo 17 spacecraft took a photograph. Released by US space agency Nasa after the mission's safe return from the moon, it showed - for the first time - the fully illuminated face of the earth. Set against the cloud-streaked blue of the oceans, the lineaments of Africa, Arabia and Antarctica were all clearly on display. Here, presented at last to the gaze of humanity, was a literally cosmic image of the geography of our planet.

Two and a half millennia earlier, an unknown scribe in Iraq had drawn on a clay tablet the very earliest surviving attempt to show the world. Iraq itself - which on the Nasa photograph could just be made out at the top of the globe - was placed at the centre of an encircling ring of ocean. Mountains, marshes and the river Euphrates - all were represented.

The focus of the map, though, was the great city of Babylon. Portrayed as a massive rectangle bisected by the Euphrates, its position within the ring of the ocean only incidentally reflected its actual position within Iraq. The concern of the cartographer lay ultimately with what he would no doubt have seen as an altogether more authentic dimension of reality: if Babylon was placed at the centre of the map, then that was because the Babylonians - with the conceit that comes to a swaggering, imperial people - took for granted that their city served the cosmos as its pivot.

Between the Mesopotamian scribe and the American astronaut, then, there stretched an immense ideological as well as technological gulf. Nevertheless, not everything had changed over the course of the millennia. Nasa's photograph might not have been oriented around Washington, DC, but it spoke of a certain level of superpower self-satisfaction, even so. Nor was the photograph devoid of its own metaphysical dimensions.

Plato, in one of his dialogues, described the sphere of the world as something that a soul, ascending in a moment of supreme transcendence, might behold as fashioned "of colours more numerous and beautiful than any we have seen". In the space age the image of the planet in all its fragile beauty, set against the infinite blackness of space, prompted in many an almost religious consciousness of the commonality of human experience. Its influence over the succeeding decades - whether on third-world identity politics or environmentalism - would prove immense.

Rare, in other words, is a representation of the earth's geography so accurate and neutral that it brings with it no baggage at all. What is true of a photograph tends to be even more so of one composed by human hand. "A map," as Jerry Brotton writes in A History of the World in Twelve Maps, his fascinating and panoramic new history of the cartographer's art, "always manages the reality it tries to show." It is the truth of this observation that enables him to trace, in the way that rivers, mountains and seas have been drawn in various cultures and periods, the contours of human self-awareness as well. Peaks and troughs; disinterest and prejudice; pin-point accuracy and whole realms of experience imagined as the haunt of fearsome monsters: civilisation bears witness to them all.

Contained within his book are studies of a dozen landmark maps. These range in time from the classical to the contemporary, and in origin from Sicily to Korea. Yet for all that, the sweeping self-assurance of his title - A History of the World in Twelve Maps - should not be taken wholly at face value. If there is one truth Brotton's survey repeatedly emphasises, it is that cartographers cannot help but betray their own centre of gravity.