Blessed John Adams, Blessed Robert Dibsdale, and Blessed John Lowe were beatified by Pope John Paul II in 1987 among the 85 Martyrs of England and Wales. All three died on October 8, 1586 at Tyburn Tree in London suffering the usual method of execution for traitors: hanging, drawing, and quartering.
Father John Adams had been an ordained Church of England minister but after becoming a Catholic went to the English College at Rheims on December 7, 1579 and was ordained a Catholic priest the next December. He returned to England in March of 1581. There is some indication that he may have been captured and imprisoned soon after his arrival but that he also escaped to serve in Winchester and in Hampshire. He certainly was captured in March 1584 and banished, along with 72 other Catholic priests. Father Adams returned to the English mission in the winter of 1585 and was captured again and this time sentenced to death under the Elizabethan statute that made his presence as a Catholic priest in England an act of treason.
Father Robert Dibsdale was born in Stratford-on-Avon in a Catholic family. He attended the English College at Rheims in 1579 and returned to England on June 22, 1580 before his ordination and was arrested at Dover immediately after landing. Dibsdale was then released on September 10, 1582 and then the record of his activities is obscure until he entered the English College at Rheims again on March 1583. He was ordained a priest in the cathedral at Rheims on March 31, 1584. Father Dibsdale set out for England on August 2 that year. He was arrested near Tothill Street in London on July 24, 1586 and was imprisoned first at the Counter then at Newgate and was found guilty of treason.
Father John Lowe was born in London in 1553, the son of Simon and Margaret Lowe; they were recusant Catholics. Indications are that he studied in Douai at some point and then entered the Venerable English College in Rome on November 19, 1591--and was ordained, although we don't know where or when. He returned to England in 1583. He was captured in London on May 11, 1586 because he was overheard speaking to his mother about his aspirations to martyrdom, which he fulfilled on this date.
Notice that all three had been in England before the passage of the 1585 statute (27 Eliz.1, c. 2: "An act against Jesuits, seminary priests, and such other like disobedient persons") making their presence as priests in their native land an act of treason. Two of the martyrs returned after the statute passed having been exiled before. You may read more about them in Lives of the English Martyrs, edited by Edwin H. Burton and J. H. Pollen. (London: Longmans, Green and Co., 1914)