Ideas - The British Version (series 2)

In the first programme, Tristram traces the story of British geographer Sir Halford Mackinder and his 'Heartland Theory'. Mackinder argued that the geography of Eurasia meant that Russia and its border countries constituted a vast fortress, land-locked and impregnable - and that if this 'Heartland' ever fell under the control of a single Great Power, it would give it the potential to dominate the world.

HIs idea, first aired in 1904, was largely ignored in Britain, but in the years after World War I, it was taken up - and twisted into a disturbing new shape - by a German geopolitician called Karl Haushofer. Haushofer tutored Hess and Hitler while they were in prison in Munich in the 1920s. Haushofer drew on Mackinder to argue that Germany should form a grand alliance with Russia and Japan, in order to dominate the Heartland.

So when news of the Nazi-Soviet Pact surprised the world in 1939, US interest in Mackinder's theory spread like wildfire. In the early 1940s, books, articles and even a Frank Capra propaganda movie - which Tristram watches with Mackinder's biographer - spelt out Haushofer's perversion of Mackinder's idea into a 'Nazi plan for world domination'.

As it became clear that Germany would lose, the elderly Mackinder was reached in his West Country bolthole by New York's Foreign Affairs magazine. FA's Managing Editor shows Tristram the letters between his predecessor and Mackinder, and explains how the resulting article helped to set the stage for post-war geopolitics.

This series was first broadcast in Autumn 2009.

Tristram Hunt on how a British geopolitical idea about Eurasia influenced foreign policy.

With a new Supreme Court opening in the UK, historian Tristram Hunt looks at the idea behind it: the separation of powers. He examines how the doctrine was developed by the French Enlightenment thinker Montesquieu, who observed the British constitutional system in the 18th century - comprised of a judiciary, an executive and a legislature - and saw it as a way of keeping tyranny at bay. Tristram starts his journey in Paris where an absolute monarchy during the 1720s led to a fierce underground debate about liberty. Ideas flowed between Paris and London and Montesquieu crossed the English Channel to better understand the English Constitutional system and the English. One of the outcomes of this was his magnum opus 'The Spirit of Laws', which articulates the importance of the 'separation of powers' to defend liberty. This idea was central to the framing of the U.S. Constitution and Tristram sees how the doctrine is embodied in the layout of Capitol Hill in Washington D.C., reflecting the relatonships between the Supreme Court, the Senate and the White House. Finally, he returns to the new Supreme Court in London to discuss whether it is, in fact, a 300 year old British idea returning home.

This series was first broadcast in Autumn 2009.

Tristram Hunt explores the idea behind the UK's Supreme Court - the separation of powers.

The Garden City was the utopian brain-child of a humble British clerk, Ebenezer Howard. He imagined a new kind of settlement that would fuse the best of town and country, creating not just decent living places for ordinary people, but a new social harmony. Unlike many utopian schemes, in 1903 Howard managed at least a partial realisation of his dream - at Letchworth, amid the fields of Hertfordshire. But as Tristram discovers, the idea mutated, and rapidly migrated beyond our shores.

He follows Howard's influence from Letchworth, to west and north London, to suburban Paris and on to New Jersey. And he finds out how a twisted version of the Garden City model may even have had an unwitting influence on Nazi plans for occupied Poland.

Finally, he follows the trail back to Britain. Advocates of government-backed 'eco-towns' see them as a revival of Howard's Victorian dream of 'a peaceful path to real reform'. But, Tristram asks, can they really match Howard's achievements?

This series was first broadcast in Autumn 2009.

Tristram Hunt follows the surprising journey of the utopian 'garden city' idea.