Dan Snow continues his historical road trip across northern Jordan, investigating extraordinary sites which straddle centuries of history.

Having explored the vast Greek and Roman city at Jerash and discovered the fascinating Byzantine town of Umm El Jamal in the first episode, Dan now heads into the desert to glimpse the spectacular legacies of the early Islamic period of over 1,200 years ago at the pleasure palace of Qusayr 'Amra.

In Jordan’s mountains, Dan traverses the military landscape of the Crusades, when the green hills overlooking the Jordan Valley became a key medieval frontline. His journey encompasses the great Saladin’s campaigns in the region, and also those of the Arab forces during the First World War. Fighting alongside them was T.E. Lawrence, made famous as Lawrence of Arabia.

In this landscape of deserts and mountains emerged a vital crossroads linking ideas, armies and trade - it is a part of the world seemingly never overlooked by history.