Edmund Campion (b. 1540–d. 1581) was born in London and educated there and at Oxford, as a member of the newly founded St John’s College, a pillar of Mary Tudor’s Catholic revival. By the time he graduated Mary had been succeeded by Elizabeth I and Catholicism by an episcopally led form of Protestantism. Campion remained in Oxford, as tutor, lecturer, and orator, and was ordained as a deacon of the Church of England in 1569, but retained strong Catholic sympathies. In 1570 Elizabeth was excommunicated by Pius V and Campion retreated to Ireland. The following year he made his way to Douai in the Spanish Netherlands, where he recanted his Protestantism, and, in 1573, proceeded to Rome, where he entered the Society of Jesus. His Jesuit novitiate was undertaken in Brno, after which he taught in Prague. In 1579 he was chosen to undertake a mission to England, supporting those of his fellow countrymen who had remained loyal to Rome and endeavoring to convert those who had not. Together with Robert Persons (or Parsons [b. 1546–d. 1610]) and Ralph Emerson, Campion left Rome in April 1580. Arriving in England, he issued a challenge to debate doctrinal matters with leading Protestants. This was his so-called Brag. It was followed by the lengthier Rationes decem. All the while, he ministered in secret to the Catholic minority, until he was arrested at Lyford Grange, Berkshire, on 17 July 1581. During his imprisonment in the Tower of London he was granted his wish to debate with Protestant divines, but the four events were rigged against him. In November he was tried and found guilty of treasonable conspiracy against the queen, and on 1 December hanged at Tyburn with two other priests, Ralph Sherwin and Alexander Briant. He was beatified by Leo XIII in 1886 and canonized (as one of the Forty Martyrs of England and Wales) by Paul VI in 1970. As this article confirms, Campion’s story is related in numerous Reference Works, expanded and/or placed in context in Overviews and examined in detail in Journals and Collections of Papers. For present purposes, his career is divided chronologically: up to 1570 under London and Oxford, 1570–1571 under History of Ireland, and the self-explanatory Mission to England, 1580–1581, which is subdivided into Primary Sources and Analysis. His afterlife is addressed under Legacy, first for the period 1581–1618, and then From Hagiography to Biography.