Macdonald Gill's striking map of the 'Highways of Empire'.

Macdonald Gill had been commissioned in the late 1920s to produce a series of promotional posters for the Empire Marketing Board, an organization formed in May 1926 by the Colonial Secretary Leo Amery. Ostensibly designed to promote intra-Empire trade and to persuade consumers to 'Buy Empire', it was actually established as a substitute for tariff reform and protectionist legislation, and thus would be abolished in 1933, as a system of Imperial Preference replaced free trade.

The 'Highways of Empire' map was the first of the over 800 maps produced by the Empire Marketing Board to be published. Unveiled on 1st January 1927, in London's Charing Cross Road, the 20ft by 10ft poster, with its slogan "Buy Empire Goods From Home and Overseas", proved so striking "as to cause congestion of the highways of London" (Manchester Guardian, 1st January 1927). Owing to its popularity, smaller reprints of the poster were published in May 1927, of which the present map is an example, with letterpress text written by Gill replacing the slogan below the map.

The projection of the map is unusual. Instead of the conventional Mercator projection, Gill shows the world - through a fundamentally imperialist lens - as it would appear from an aeroplane above London, with the aim to give "a vivid idea of how the British Empire is scattered in relation to the home country".

Dotted across the map is a "jolly" menagerie of animals and sea-creatures, including - erroneously - polar bears in the South Pole. This blunder Gill and Sir Stephen Tallents, Secretary of the Empire Marketing Board, only realized the night before the map was due to be exhibited to a variety of world leaders, at the Imperial Conference of 1926: "a gaffe which, full allowance being made for the ignorance of natural history common among Prime Ministers, was likely to be spotted by the Prime Minister of New Zealand" (Tallents, 'Advertising and Public Relations Today', 1955, p.96). The situation was saved by the speech-bubbles added to the bears, so that one, confused, asks "why are we here? We belong to the North Pole!" and the other sings "it's a long long way to Tipperary".