Glastonbury was one of the richest abbeys in the kingdom, and one of the best run and most observant of the Rule of St. Benedict: it was a ripe target for Henry VIII, Thomas Cromwell, and the Court of Augmentations. Reading Abbey was a Benedictine house established during the reign of King Henry I and dedicated to Our Lady and St. John the Evangelist. It was initially part of the Cluniac branch of the Benedictine order. Cromwell had to trump up some charges against the elderly abbot at Glastonbury, because his Visitor first reported that everything was managed very well there; the monks were observant of the Benedictine Rule. Cromwell told Richard Layton to look further: hisjob was not to find excellence but detect failure as the the excuse for suppression. Both Abbot Whiting and Abbot Faringdon of Reading Abbey had gone along with Henry VIII's claims of supremacy over the Ecclesiae Anglicanae.
More about the martyrs at Glastonbury here and about those at Reading. Perhaps their martyrdoms expiated their guilt for denying the authority of Christ's Vicar on earth: These six martyrs of the Dissolution of the Monasteries on November 15, 1539 (three each at Reading and Glastonbury) represent in some ways the remorse of the abbots and abbey leadership, who had accepted Henry VIII's oaths that proclaimed his authority over the Church of England as Supreme Head and Governor. Somehow they did not realize or imagine what he could and would do with that power and authority.
Pope Leo XIII beatified these six monastic martyrs in 1895.