Saint Oliver Plunket was born in Loughcrew, county Meath, in 1629.
Oliver's youth was spent in the upheaval of the rebellion against Charles I, where his family of the noble gentry class supported the prerogative of the King, and sought freedom for the Irish.
He was sent at 16 to Rome to be instructed with four others under Fr. Pierfrancesco Scarampi, and Oratorian of well known respect. After completing his studies, St. Oliver was subsequently ordained, and due to the strife of Ireland, was appointed to and maintained the chair of Theology at the College de Propaganda Fide for 12 years.
At this time, Edmund O'Reilly, the Archbishop of Armagh and primate of Ireland, spent only two of his twelve years in his See, spending the rest in exile in France. When he died in 1669, St. Oliver was consecrated to take the place of O'Reilly. He ventured to England, spending time hidden in the company of the almoner of Charles II, a Dominican. From there he arrived in Dublin in 1670.
Within three months, he had convened a synod, exacted two ordinations, and administered the Sacrament of Confirmation for 10000 souls - with still easily 50000 eligible for confirmation after. Politics would soon interrupt his reforms, as a dispute arose over the primacy of his See in Ireland. He insisted the primacy of the See of Armagh held juridictional oversight of the other Sees, but the others felt it was a titular position, and therein lies the strife.
Archbishop Plunket also had numerous religious and political battles: laxity amongst clergy and laity; conflicts between Ordered clergy, and the secular clergy and friars; installation of Jesuits to teach children and seminarians; oppression by Protestant civil authorities; the heresy of Jansenism influencing clerics and laity; and all this with a lack of the funds necessary to administer the See.
King Charles II began another round of persecution in 1673, and most Bishops were forced to flee or go into hiding, with St. Oliver in the latter category. The hiding was made worse by the presence of a group of schismatic or quasi-schismatic Catholics. In 1678, the Oates Plot was executed. All bishops and clerics were expelled from Ireland.
An expelled Franciscan and an excommunicated priest snitched out our saint in London. He was arrested and put in Dublin prison. When the obviously false assertions (he was supposedly "attempting" to bring 40000 French soldiers into secure the popish plot) of his captors failed to materialize, St. Oliver was transferred to London. There he was dubiously convicted of his crimes.
On the first of July, 1681, Saint Oliver Plunket was before a crowd that pleaded for his innocence, and prayed for him and his enemies. He was hung, disimbowelled, and quartered. His relics were buried in London, but ultimately ended up in several locations throughout Ireland.