In episode one of our series on the First Crusade, we consider how a landmark papal bull lit a fire under the idea of crusading, triggering a military machine that saw tens of thousands make an unprecedented journey into the unknown and face off against an unfamiliar enemy

When we talk about the crusades today the mental images that spring to mind are as clear as they are striking – valiant crusader knights emblazoned with crosses and penniless pilgrims in search of salvation, perhaps even a brutal clash of civilisations. But, there's more to them than that. In the first episode of our latest HistoryExtra podcast series, we’re travelling back in time to where it all started, uncovering the origins of the First Crusade. Speaking to a range of expert historians, we trace how a complex web of ideas and problems came together to form a major movement, fired with religious zeal.

The HistoryExtra podcast is produced by the team behind BBC History Magazine and BBC History Revealed.
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