Henry V had just been crowned; but the first crisis of his reign was an attempted insurrection against him in London; a group of religious extremists banded together to kill him… but why? Who were the Lollards and how did events get so serious? In this, the first of two episodes on the rebellion, we look at the secret history of the group, and see that for decades, they had existed hidden in plain sight within London’s streets, growing in number but seemingly ignored by the city authorities…