Just east of where the Strand turns into Fleet Street in London, there is a small stone archway. Walking through it, one stumbles across a hidden world – one that is leafy, serene and historic. Most of the people who wind their way here don’t realise that the whole area was actually the stronghold of the Knights Templar – and that it is here we find the extraordinary Temple Church. As a round church modelled after the Holy Sepulchre of Jerusalem, Temple Church was the closest people in the Middle Ages could get to Jerusalem without actually undertaking a pilgrimage. It was also within this light-filled building that the English order of the Knights Templar – valiant, daring Crusaders - would meet, worship and even be initiated into the order. Inside the church, we also find the stone effigy of one of the most violent and celebrated men of the Middle Ages: William Marshall. A famous knight, a key political player and the eventual Regent of England, Marshall rose from relative obscurity to become one of the most important men in the country. A man as famous for his roguish antics as his formidable strength, Marshall became one of the defining figures to be associated with the Knights Templar. In this captivating documentary, Dan Jones leads us through the immensely atmospheric Temple, and relays some of the tales of William Marshall’s extraordinary life.