Fathers Thomas Ford, John Shert, and Robert Johnson were hung, drawn, and quartered at Tyburn on May 28, 1582. According to the Catholic Encyclopedia, Thomas Ford was:
Born in Devonshire . . . He incepted M.A. at Trinity College, Oxford, 14 July, 1567, and was a fellow, Woods says president, of the college. He went to the English College, Douai, in 1570, and was one of the first three of its students to be ordained, receiving all orders in March, 1573, at Brussels. After becoming B.D. at Douai he left for England, 2 May, 1576, and soon became chaplain to Edward Yate and his Bridgettine guests at Lyford, Berkshire. Arrested with St. Edmund Campion 17 July, 1581, and committed to the Tower 22 July, he was thrice tortured. He was brought before the Queen's Bench 16 November, with his fellow martyr Blessed John Shert, on an absurd charge of conspiracy at Rome and Reims, where he had never been, on dates when he was in England, and both were condemned 21 November.
So he was held (and tortured) from July 1581 until trial in November 1581, but not executed until May 1582. In addition to his connection with St. Edmund Campion, Thomas Ford had aided the protomartyr St. Cuthbert Mayne:
Late in 1570 a letter from Gregory Martin to [Saint] Cuthbert fell into the Bishop of London's hands. He at once sent a pursuivant to arrest [Saint] Cuthbert and others mentioned in the letter. [Saint] Cuthbert was in the country, and being warned by Blessed Thomas Ford, he evaded arrest by going to Cornwall, whence he arrived at Douai in 1573.
You may read details of Ford's arrest and capture with St. Edmund Campion here.
John Shert, according to the same source, was also held in prison a long time:
The Diocese of Shrewsbury adds these details about his trial and execution:
He was the second of three priests to die at Tyburn on 28th May 1582 and was made to watch as the first, Blessed Thomas Ford, was butchered, shouting with arms outspread: “O happy Thomas! You have run that happy race. You blessed soul, pray for me.”
When it was his turn to die, Blessed John rejected an invitation from the Sheriff to request the Queen’s forgiveness on the grounds that he was guilty of no offence. He also refused an offer of clemency if he admitted treason with the words: “Should I for saving this carcass condemn my soul? God forbid!”
He did, however, acknowledge Queen Elizabeth as the legitimate English sovereign but not as the supreme governor of the Church in England. “She is not nor cannot be, nor any other, but only the supreme pastor,” he said.
To the crowd baying for his blood he left the admonition: “Extra ecclesiam nulla salus” (there is no salvation outside of the Catholic Church).
Finally, Robert Johnson:
Shrewsbury offers this detail about his trial and execution:
During the trial Blessed Robert gave evidence against claims by George Eliot, the renegade Catholic who betrayed Campion, that he and St John Paine had tried to persuade him to join a plot against Elizabeth. All the defendants were convicted, however, in spite of the lack of evidence against them. Campion, St Ralph Sherwin and St Alexander Briant were executed almost straight away. But Blessed Robert was held in custody until 28th May the following year when he was drawn face down on a hurdle to the Tyburn Tree along with Blessed John Shert, another Shrewsbury priest, and Blessed Thomas Ford.
Blessed Robert was the last to die, after being forced to watch the quartering of Blessed John. He went to his death vowing his loyalty to the Queen and protesting his innocence of treason, saying: “I teach (nothing) but the Catholic faith”.
When the Sheriff accused him of being a traitor he replied: “If I be a traitor for maintaining this faith then all the kings and queens of this realm heretofore, and all our ancestors, were traitors for they maintained the same.”
So why the long delay in their executions? Saints Edmund Campion, Ralph Sherwin, and Alexander Briant had all been executed on December 1, 1581, not long after the trial. Dom Bede Camm suggests in his Lives of the English Martyrs, published in 1916, that the Elizabethan government recognized that their efforts to curtail the flow of missionary priests through execution had failed and that the trumped up conspiracy charges had also been exposed as false. Camm notes that a pamphlet issued by the government to demonstrate the "traitorous affection" of Campion and the other priests didn't even mention the "Rome and Rheims Plot". Therefore, the remaining "conspirators" were asked a series of "bloody questions" about Pope Pius V's papal bull Regnans in Excelsis, Queen Elizabeth's supremacy and legitimacy as monarch, the Northern Rebellion, etc. Of course, their responses to these questions are opinions, not actions against the state or the monarch. Their responses may attest to their "traitorous affections" but are not acts of treason for which a person may be condemned and executed, even under English Common Law at that time. So both the trial and this extra-judicial questioning were unjust.
Pope Leo XIII beatified 54 martyrs of England and Wales on December 29, 1886 and these three were among that group. Blessed Thomas Ford, Blessed John Shert, and Blessed Robert Johnson, pray for us!