Thank you for downloading this episode of a history of the world in a hundred objects

from BBC Radio 4.

There's a compelling showbiz mythology of the modern big city, the energy and the abundance,

the proximity to culture and power, the streets that just might be paved with gold.

We've seen it and we've loved it on stage and on screen.

But we all know that in reality big cities are noisy,

potentially violent and alarmingly anonymous. We sometimes just can't cope

with the sheer mass of people.

Apparently if you look at how many numbers we're likely to store in our mobile phone

or how many names we're likely to list on a social networking site,

it's very rare even for city dwellers to exceed a couple of hundred.

Social anthropologists delightedly point out that this is the size of the social group we'd have had to

handle in a large stone age village. According to them, we're all still trying to cope

with modern city life with a stone age social brain. So how do you lead and control a city or a

state where most people don't know each other and you can only personally

persuade a very small percentage of the inhabitants.

It's the central theme of this week's programs.

And it's been the key political question for over 5,000 years,

since the growth of the world's first cities and states.

These grew up in the world's great fertile river valleys,

the Euphrates, the Tigris and the Indus, but I want to start with the most famous river of them all.

The Nile.

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