The Spanish Civil War offered one of the most enduring images of all, caught by the camera of the legendary Robert Capa - a Republican soldier at the instant of death, the moment of truth, the bitterest truth of all.
And now we see again how potent a picture can be. Not long ago it seemed certain that the lasting image of war in Iraq would be Saddam's toppled statue. Instead, for millions, it is now a grinning 21-year-old girl holding a dog lead attached to the neck of a naked, cowering Iraqi.
That the mass media grew in importance during the twentieth century cannot be doubted. The late Victorian period witnessed an enormous expansion of the press, stimulated by improved technology and by the mid-century removal of the so-called 'taxes on knowledge', the stamp and paper duties which had raised the price of newspapers. By 1901 there were 21 major daily newspapers being produced in London. Although this number was to fall in the next few decades, as a result of closures and mergers, the press would remain a power in the land, courted and feared by politicians of all parties.
After the First World War new media came to rival the press in their capacity to reach a mass audience. The cinema came into its own in the inter-war period, providing newsreel images which enabled the public at large to gain its first visual appreciation of the country's political leaders. The establishment in the 1920 of the BBC made possible the supply of radio, followed later by television, directly to voters' homes. From 1955, with the emergence of independent television, the BBC's monopoly of broadcasting was challenged by the rise of commercial channels. The appearance of satellite and cable television from the late 1980s further extended the variety of media available to the public.
The role of the media in politics remains an area of intense debate. Although the press and broadcasting have rarely, if ever, been direct causes of political change, arguably they have done more than merely reflect their environment. The historians James