Born: 1560, County Clare / Bodmin, Cornwall
Entered: July 1584
Ordained: September 1583
Died: 04 July 1594, Dorchester, Dorset, England (Martyr) - Angliae Province (ANG)

http://www.clarelibrary.ie/eolas/coclare/history/frost/chap5_east_corcabaskin.htm
In MacBrody’s Propugnaculum Catholiæ Veritatis it is stated that John, son of Conor MacMahon, of Knockalocha, by his wife Bridget Brody, daughter of “Darii” Mac Bruodin, of Mount Scot, was invited at the age of ten by his uncle Thomas MacMahon, who was living with the Earl of Arundel, to go over to England and live amongst the Earl’s pages. He was thence sent to Rome to study, and was there admitted into the Society of Jesus. He returned to England afterwards, and was hanged, drawn, and quartered, in 1594.[11]

11. Brody in mistake states that this M‘Mahon was of Tuath-na-farna.

◆ Fr Edmund Hogan SJ “Catalogica Chronologica” :
Two Entries John MacMahon and John Cornelius

DOB 1557 Clare or Bodmin, Cornwall of Irish parents; Ent shortly before execution RIP 04 July 1594
Known in England as John Cornelius and of ANG
Born of Irish parents; A man of extraordinary piety; Hanged, drawn and quartered at Dorchester

Studied at Oxford for several years by means of his kind patron, Sir John Arundell, Knight, of Laherne, Cornwall. “Misliking the new religion” he was sent to Rheims, and after a period there some say he entered the English College Rome for higher studies and Theology 01 April 1580. In his second year Theology, he was selected to make the usual Latin oration before the Pope in the Sistine Chapel, on the Feast of St Stephen the proto-martyr. He was Ordained there 1583 and went to England.
After working in England for a few years he was seized at Chideock Castle, Dorset, where he was Chaplain to Lady Arundell, the widow of Sir John, 14 April 1594. He was carried off to London, where he was examined and remanded to Dorchester for trial, and having been condemned to death for the priesthood, was admitted to the Society in prison, before execution 04 July 1594, with his three fellow captives, Thomas Bosgrove Esq, a relative of the Arundells and probably brother of James Bosgrove SJ, John Carey and Patrick Salmon - servants at Chideock.
(cf “Records SJ” Coil IV, and Vol iii pp 435 seq, and Vol vi p141; Foley’s Collectanea)

There is also a long note from Foley’s Collectanea regarding the possibility of finding relics of the Dorset Martyrs, specifically the heads, including those of John Cornelius.)

◆ James B Stephenson SJ Menologies 1973
Blessed John Cornelius (MacMahon) 1557-1594
Blessed John Cornelius, who crowned a life of sanctity with martyrdom on July 4th 1594, was born the only son of Irish parents at Bodmin in Cornewall in 1557.

His parents were not wealthy, but his aptitude for study aroused interest of Sir John Arundell of Lanherne, and he became his patron, sending him to Oxford, then to Dr Allen at Rheims and finally to the English College at Rome in 1580.

He returned to England a priest in 1583 and his first care was to bring back to the Church his widowed mother.

Taking little care of the priest-hunters, he evangelised the Catholics in different places, in all kinds of weather, and mostly in the dead of night. His sanctity gave him power over evil spirits and he was frequently rapt in divine contemplation.

After many vain attempts to capture him, he was finally taken prisoner in March 1594. He was allowed to take leave of his sorrow stricken mother before being taken to London and lodged in the Marshalsea. Here for two months he was subjected to inhuman torture. Finally he was brought to Dorchester for execution. On the evening before execution, he begged leave to be taken to the foot of the scaffold where he spent some time in contemplation.

At two o’clock on the following afternoon, July 4th 1594, he was led forth to the scaffold, with great reluctance it must be said on the part of the judge and executioner, so great an impression his holiness had made on all. Indeed, many petitions were made on his behalf to the Court, but he himself only aspired after eternal life. “Grant me” he cried “Sweet Jesus, that the alone may be the object of my words and actions”.

◆ http://www.clarelibrary.ie/eolas/coclare/history/frost/chap5_east_corcabaskin.htm
In MacBrody’s Propugnaculum Catholiæ Veritatis it is stated that John, son of Conor MacMahon, of Knockalocha, by his wife Bridget Brody, daughter of “Darii” Mac Bruodin, of Mount Scot, was invited at the age of ten by his uncle Thomas MacMahon, who was living with the Earl of Arundel, to go over to England and live amongst the Earl’s pages. He was thence sent to Rome to study, and was there admitted into the Society of Jesus. He returned to England afterwards, and was hanged, drawn, and quartered, in 1594.[11]

11. Brody in mistake states that this M‘Mahon was of Tuath-na-farna.

In Old/15 (1), Old/16, Old/18 and Old/19

◆ George Oliver Towards Illustrating the Biography of the Scotch, English and Irish Members SJ
CORNELIUS, JOHN, was born at Bodmin, and became a protege of Sir John Arundell, of Lanheme, commonly called the Great Arundell (as More informs us, p. 165), who kindly defrayed the expences of his education at Oxford. The youth, to keep his conscience, left Oxford for the seminary at Rheims, with the approbation of his worthy Patron, and was favourably received by the incomparable Dr. Allen. With five others, viz. James Lomax, Christopher Southworth, John Tippet, Simon Swinburn, and Robert Charnock, he was sent by Dr. Gregory Martin, and the other Superiors of the House, to the English College at Rome, on 9th February, 1580, who testify to F. Agazzari “omnes nostro judicio idoneos, et ad vestram expectationem aetate, ingenio, moribus ac eruditione convenienter (quantum in nobis erat) electos atque approbatos”. After finishing Theology and receiving Priesthood, F. Cornelius re turned to England in September, 1583. His generous patron on his death-bed earnestly recommended to his wife (Anne, daughter of Edward, Earl of Derby, and relict of Charles the seventh Lord Stourton) the care of his rev. friend. From the pen of her daughter Dorothy Arundell, who afterwards became a Nun at Brussels, and employed him for ten years as her spiritual director, we learn most of the following particulars :
For some time he resided in London with the Arundell family. His fame for dispossessing obsessed persons becoming notorious, the Privy Council decided on apprehending him : a posse of thirty constables had actually invested the house of a Catholic gentleman at Mile End, where F. Cornelius happened to be : he was engaged in writing when apprised of their arrival : with perfect calmness he left his chamber, and passed through the midst of them unheeded, unsuspected, and unmolested.
Lady Arundell and her establishment quitting town for Chidiock Castle, F. Cornelius accompanied them. The fruits of his zeal soon appeared in the reconciliation of above thirty families. But we can be surprised at nothing, when we call to mind his seraphic charity, his uninterrupted union with Almighty God, and his very mortified life. And “he was so famous for his preaching”, says F. Gerard, “that all Catholics followed him, as children do their nurse, when they long for milk”.
This great and good man had for several years cherished a vehement desire of being incorporated with the Society of Jesus, and had applied to the General Aquaviva for admission. In a letter written to that Chief Superior about the year 1592, by F. Hen. Garnet, I read “Joannes Cornelius vir notae pietatis hoc de se asserit paratum se quidem esse in Flandriam ire, si jubeamus - vir vere humilis, pius et sanctus est, et demonibus, terribilis, quippe qui ejus nuper in Exorcismis mire exagitaverit; et ejus apud nostrates existimationis, dignys ut sit qui nostris humeris feratur. Votum Societatis ingrediendae emisit. Vestram Dominationem ed de re consuluit una cum D. Loo, praestanti jamdudum Martyre. Illc ejusmodi est, ut nullum timeri pericalum posst si tyrocinium differatur et hic admittatur; et praeterea fèrè sem per virit cum uno è nostris”. But his crown was preparing.
From pure benevolence Lady Arundell was induced to employ a miserable pauper in menial offices about the Castle. After some time the man, forgetful of his situation, grew enamoured, in his folly, of her Ladyship’s maid, a most respectable person, and annoyed her with his attentions and proposals. Complaint was made to the chaplain, who seriously remonstrated with him on the impropriety of his conduct. In the spirit of revenge the miscreant determined to betray the Priest, and for this purpose concerted measures with the high Sheriff of Dorset, Geo. Morton, Esq., and two Justices of the Peace, George Trenchard, and Ralph Horsey, Esqrs. Easter Sunday, 31st March, 1594, was fixed upon for the attempt, and for five miles round the castle the paths and roads were guarded with police. Suspicious of danger F. Cornelius said Mass for the family as early as one o’clock that morning, and notwithstanding their intreaties to the contrary, he then hurried away and lay prostrate on the ground, within a thick copse at some distance; the searchers came, but after two days of fruitless labour and expectation, retired dissatisfied and provoked with their informer. Unwilling to expose the family to a repetition of such vexatious visits, and to endanger their property, liberty, and lives, this considerate chaplain proposed to leave Chidiock, at least for some time, but Lady Arundell would not consent, and accordingly he resumed his usual ministry. His return was duly notified to the magistrate by the domestic enemy. On 14th April, the second Sunday after Easter, Cornelius said Mass at 5 o clock, and whilst making his thanksgiving, Mr. Trenchard and his satellites, having rapidly scaled the outer walls, and burst open the castle doors, entered with drawn swords and loud clamours, and dispersed themselves over the house in every direction, Cornelius had time to take refuge in his hiding hole. For five or six hours the search was conducted with eager diligence; but nothing was found except books and ornaments for the altar. The magistrate was then preparing to retire, when he was solicited to continue for some time longer : the faithless servant heading the party to the chamber where the hiding hole was. F. Gerard states, that the breathing or coughing of the Priest was the means indeed by which he was found out and apprehended; but unquestionably attention to the spot had been directed by the traitor. On forcing the secret entrance, the Father appeared absorpt in meditation. Their brutal shouts brought in Miss Dorothy : he appeared paler than usual, but refulgent with light, and the was so overcome with the scene as to be incapable of utterance. I am glad, said the magistrate, that we have caught you at last. “I am doubly contented”, said Cornelius. Leading him into the hall, he was subjected to an examination as to his profession : he begged them previously to understand, that he owed it to justice and charity to maintain an impenetrable silence as to points that might be detrimental to other persons; but as to his profession and his religion, he was prepared to defend it with zeal and modesty. The members of the family were then introduced one by one, and questioned as to their knowledge of the prisoner. They affected ignorance of his person, with the exception of Mr. Thomas Bosgrave, her ladyship’s kinsman (and probably connected with F. James Bosgrave), who manifested the most profound respect and veneration for this confessor of the faith. Miss Dorothy at last appeared, and with a sorrowful countenance took all the blame (if any) upon herself, of harbouring the gentleman : she had invited and concealed him; but under the conviction that instead of violating the law, she was performing an act of Humanity. His mother, a poor Irish woman, aged, decrepid, and bed-ridden, lived in the house, and had hoped for the consolation of beholding her son once more. Would a Barbarian refuse this tribute of natural piety and affection?
Commitments were made out for four, the Priest, Mr. Bosgrave, and two servant men, Patrick Salmon, and John (alias Terence) Cary. After bidding an affectionate adieu to his afflicted mother, and animating her to confidence in a Fatherly Providence, the good Priest mounted a horse, and rode by the side of the magistrate, like a companion and friend. At the venerable castle-gate about five hundred persons had collected. Cornelius saluted them courteously, and they returned the compliment with every mark of sympathy and respect. Trenchard was of a humane disposition : he allowed his prisoner during the fortnight he remained at his house, every accommodation compatible with safe custody. Many flocked to converse with him : amongst others, Charcke, the vanquished opponent of F. Persons, and Sir Walter Raleigh. The latter spent a whole night in discussing controversial topics, and departed with admiration of his talents, and with complimentary proffers of service,
On 30th April, orders arrived from the Privy Council to send up the prisoner to London. Here he was lodged in the Marshalsea, and most inhumanly tortured; but his constancy was immovable. His prison he regarded as a Paradise; for it furnished the long desired opportunity of entering into the Society of Jesus. He pronounced his vows before a Religious, commissioned by F. Hen. Garnet to receive them in the presence of two witnesses. He tells Dorothy in a letter, that his heart is now swimming with joy, for this favour of Almighty God : and when he was “going to die for a moment, that he might live for ever”, to use his own expression, he publicly professed himself to be a Jesuit.
Remanded to Dorchester, he approached the gibbet with all the joyful welcome of a St. Andrew. With his three companions, he suffered there on 4th July, 1594. In a memorandum of Richard Verstegan, the antiquary, I read, “they could not get a cauldron for any money to boyle his quarters, nor no man to quarter him : so that he hanged until he was dead; and was buried, being cut in quarters first”. It is certain, however, that the quarters were exposed for a time, and that the head was nailed to a gallows; and moreover, that by the management of the above-mentioned Lady Arundell, the quarters were by stealth conveyed away, “furtim sublata et honorificentius collata”. The head also came into the possession of Catholics. “Caput etiam venil in Catholicorum potestatem”.
The reader will be as much edified with his Biography in FF. More and Tanner’s History, and in Dr. Challoner s faithful Memoirs, as he will be disappointed with the meagre and defective narrative in p.73-4, of vol. ii. of Dodd s Church History.

• This conscientious Knight was summoned up to London early in 1581, and committed to close custody for a time by Queen Elizabeth. He died at Isleworth, as we learn from the parish register, 17th January. 1591, but was buried at St. Colombs. His servant Glynn, actually died a prisoner for religion.

• This most worthy Priest had suffered at Tyburn, as early as 8th October, 1586.

• F. Gerard was intimate, amongst others, with F. Cornelius. In a MS written about 1607, he stiles him the third martyr of the Society of Jesus in England, (Campian and Briant had suffered before him) adding, “The man was so full of the Apostle’s charity, that with one fervent speech (in imitation of the offer which St. Paul made to be anathema pro fratribus) he expelled a devil out of a person whom he was exorcising. I know the time and place where it was performed; and where another wicked spirit confessed in a possessed person, that this fellow was cast out by Cornelius charity”.