Oliver Plunkett (Irish: Oilibhéar Pluincéid), Catholic Archbishop of Armagh and Primate of All Ireland who is the last victim of the Popish Plot, is executed in Tyburn, London, England, on July 1, 1681. He is beatified in 1920 and canonised in 1975, thus becoming the first new Irish saint in almost seven hundred years.

Plunkett is born on November 1, 1625 (earlier biographers give his date of birth as November 1, 1629, but 1625 has been the consensus since the 1930s) in Loughcrew, County Meath, to well-to-do parents with Hiberno-Norman ancestors. A grandson of James Plunket, 8th Baron Killeen (c. 1542-1595), he is related by birth to a number of landed families, such as the recently ennobled Earls of Roscommon, as well as the long-established Earls of Fingall, Lords Louth, and Lords Dunsany. Until his sixteenth year, his education is entrusted to his cousin Patrick Plunkett, Abbot of St. Mary’s, Dublin, and brother of Luke Plunket, 1st Earl of Fingall, who later becomes successively Bishop of Ardagh and of Meath.

As an aspirant to the priesthood, Plunkett sets out for Rome in 1647, under the care of Father Pierfrancesco Scarampi of the Roman Oratory. At this time the Irish Confederate Wars are raging in Ireland. These are essentially conflicts between native Irish Catholics, English and Irish Anglicans and Nonconformists. Scarampi is the Papal envoy to the Catholic movement known as the Confederation of Ireland. Many of Plunkett’s relatives are involved in this organisation.

Plunkett is admitted to the Pontifical Irish College in Rome and proves to be an able pupil. He is ordained a priest in 1654, and deputed by the Irish bishops to act as their representative in Rome. Meanwhile, the Cromwellian conquest of Ireland (1649–53) had defeated the Catholic cause in Ireland. In the aftermath the public practice of Catholicism is banned and Catholic clergy are executed. As a result, it is impossible for Plunkett to return to Ireland for many years. He petitions to remain in Rome and, in 1657, becomes a professor of theology. Throughout the period of the Commonwealth and the first years of Charles II‘s reign, he successfully pleads the cause of the Irish Catholic Church, and also serves as theological professor at the College of Propaganda Fide. At the Congregation of Propaganda Fide on July 9, 1669 he is appointed Archbishop of Armagh, the Irish primatial see, and is consecrated on November 30 at Ghent by the Bishop of Ghent, Eugeen-Albert, count d’Allamont. He eventually sets foot on Irish soil again on March 7, 1670, as the Stuart Restoration of 1660 had begun on a basis of toleration. The pallium is granted him in the Consistory of July 28, 1670.

After arriving back in Ireland, Plunkett tackles drunkenness among the clergy, writing, “Let us remove this defect from an Irish priest, and he will be a saint.” The Penal Laws had been relaxed in line with the Declaration of Breda in 1660 and he is able to establish a Jesuit College in Drogheda in 1670. A year later 150 students attend the college, no fewer than 40 of whom are Protestant, making this college the first integrated school in Ireland. His ministry is a successful one and he is said to have confirmed 48,000 Catholics over a four-year period. The government in Dublin, especially under the Lord Lieutenant of Ireland, James Butler, 1st Duke of Ormonde (the Protestant son of Catholic parents), extend a generous measure of toleration to the Catholic hierarchy until the mid-1670s.

On the enactment of the Test Act in 1673, to which Plunkett does not agree for doctrinal reasons, the college is closed and demolished. He goes into hiding, travelling only in disguise, and refuses a government edict to register at a seaport to await passage into exile. For the next few years he is largely left in peace since the Dublin government, except when put under pressure from the English government in London, prefer to leave the Catholic bishops alone.

In 1678 the so-called Popish Plot, concocted in England by clergyman Titus Oates, leads to further anti-Catholic action. Archbishop of Dublin Peter Talbot is arrested, and Plunkett again goes into hiding. Despite being on the run and with a price on his head, he refuses to leave his flock. He is arrested in Dublin on December 6, 1679 and imprisoned in Dublin Castle, where he gives absolution to the dying Talbot. He is tried at Dundalk for conspiring against the state by allegedly plotting to bring 20,000 French soldiers into the country, and for levying a tax on his clergy to support 70,000 men for rebellion. Though this is unproven, some in government circles are worried about the possibility that a repetition of the Irish Rebellion of 1641 is being planned and, in any case, this is a convenient excuse for proceeding against Plunkett.

Plunkett is found guilty of high treason in June 1681 “for promoting the Roman faith,” and is condemned to death. Numerous pleas for mercy are made but Charles II, although himself a reputed crypto-Catholic, thinks it too politically dangerous to spare Plunkett.

Plunkett is hanged, drawn and quartered at Tyburn on July 1, 1681, the last Catholic martyr to die in England. His body is initially buried in two tin boxes, next to five Jesuits who had died previously, in the courtyard of St. Giles in the Fields church. The remains are exhumed in 1683 and moved to the Benedictine monastery at Lamspringe, near Hildesheim in Germany. The head is brought to Rome, and from there to Armagh, and eventually to Drogheda where since June 29, 1921 it has rested in St. Peter’s Roman Catholic Church. Most of the body is brought to Downside Abbey, England, where the major part is located today, with some parts remaining at Lamspringe. On the occasion of his canonization in 1975 his casket is opened and some parts of his body given to the St. Peter’s Church in Drogheda.