This letter was written by John Sumner in London on the 6th November 1605 to William Ffarington of Worden Hall in Chorley, Lancashire. The letter describes the Gunpowder Plot the day after it was discovered. Sumner says that 36 barrels of gunpowder were found "directly under the Parliament house" and when "the King, Queen and young prince, together with all the nobility and Peers of the Realm had been assembled, to have set fire upon the powder."

The 1500s and 1600s was a period of extreme religious upheaval when the official state religion changed from the Catholic to the Protestant faith. The Gunpowder plot which included the now famous Guy Fawkes, was an attempt to kill the protestant King James I, his heir and members of Parliament and to re-establish a Catholic monarchy after years of religious persecution. In this period, it was illegal to convert to Catholicism, say or hear mass or to conceal the presence of a priest.

The county of Lancashire was considered to be a catholic stronghold at the time and in 1599 four Queen's Preachers were established in the county by the Government to help convert the region. Many of Lancashire's stately homes had priest holes where clergy could be concealed if the house was searched by the authorities. Surviving examples include Samlesbury Hall near Blackburn, Thurnham Hall near Lancaster and Speke Hall in Liverpool.

During the period 1584–1646 fifteen Catholics were executed at Lancaster Castle for their faith. This included Blessed James Bell from Warrington who was executed at Lancaster in 1584 and Blessed John Thules, the son of a weaver from Chorley who was executed in 1616 after he refused to recant his faith.