On 21 October Digby, his wife Mary, Garnet and Vaux were at Harrowden celebrating a delayed Feast of St Luke. While there he met Robert Catesby, who at some point asked him to swear an oath of secrecy before introducing him to what later became known as the Gunpowder Plot. English Catholics had hoped that the years of persecution they suffered during Elizabeth's reign would end when James I came to the throne, as his attitude appeared moderate, even tolerant towards Catholics. In Catesby's view, however, James had reneged on his promises, and he had quickly lost patience with the new dynasty. He therefore planned to kill James by blowing up the House of Lords with gunpowder, and then inciting a popular revolt during which a Catholic monarch would be restored to the throne. Catesby had enlisted the aid of other Catholics, but had borne much of the scheme's financial cost and was running out of money. The group had therefore agreed to expand their numbers. To this end Catesby had recruited Ambrose Rookwood—a young and wealthy Catholic with a stable of fine horses—and a wealthy cousin, Francis Tresham.