The Diocese of Shrewsbury provides a biography of one of its two martyrs canonized by Pope Paul VI in 1970, St. John Plessington:
St John Plessington is one of two Shrewsbury saints to be canonised among the 40 martyrs of England and Wales in 1970, the other being St Margaret Ward. He is also one of six of the 40 martyred after they were accused of treason in the “Popish Plot”, which had been fabricated by Titus Oates, and which led to the deaths of more than 25 innocent Catholics in the late part of the 17th century.
Although he was born in Dimples, near Garstang, Lancashire, St John exercised his ministry in Cheshire and North Wales, and he was hanged, drawn and quartered on 19th July 1679 at Boughton Cross, overlooking the River Dee at West Chester. What is remarkable about his execution is that St John wrote his speech for the scaffold ahead of his death. It was later printed and copies still exist. According to Butler’s Lives of the Saints the speech represents “a particularly clear statement of denial in the face of death of the charges upon which he was condemned”, charges which, had they been true, would have made him a dangerous criminal rather than a martyr.
And this site provides the text of his speech:
I am here to be executed, neither for Theft, Murder, nor anything against the Law of God, nor any fact or Doctrine inconsistent with Monarchy or Civil Government. I suppose several now present heard my trial the last Assizes, and can testify that nothing was laid to my charge but Priesthood, and I am sure that you will find that Priesthood is neither against the Law of God nor Monarchy, or Civil Government. If you will consider either the Old or New Testament (for it is the Basis of Religion […], St Paul tells us in Hebrews 7:12 that the Priesthood being changed, there is made of necessity a change of the Law, and consequently the Priesthood being abolished, the Law and Religion is quite gone.
But I know it will be said that a Priest ordained by authority derived from the See of Rome is by the Law of Nation to die as a Traitor, but if that be so what must become of all the Clergymen or England, for the first Protestant Bishops had their Ordination from those of the Church of Rome, or none at all, as appears by their own writers, so that Ordination comes derivatively to those now living.
As in the Primitive times, Christians were esteemed Traitors, and suffered as such by National Law, so are the Priests of the Roman Church here esteemed, and suffer such. But as Christianity then was not against the law of God, Monarchy or Civil Policy, so now there is not any one Point of the Roman Catholic Faith (of which Faith I am) that is inconsistent therewith, as is evident by induction in each several point. . . .
Both of the websites I've linked include a picture of "a stained glass window in St Winefride’s Church, Holywell, depicts St John ministering to a kneeling woman then giving his speech on the day of his execution." It's interesting that he was allowed to give his speech in full before his execution, but like other Popish Plot martyrs, he had been serving a Catholic family in the area for several years---in his case a decade--without any trouble. It was the Popish Plot and the resulting anti-Catholic hysteria, and the added inducements to turn in any priest for reward and recognition that led to his arrest, charge, and execution.