The Feet of Fines for London and Middlesex shows him and Juliana disposing of London properties during the reign of Edward VI in the parishes of St Mary-at-Hill in the Billingsgate area and that of All Hallows-by-the-Tower or "All Saints, Barkyng". A much larger group of properties in London, Essex and Bedfordshire was disposed of in the same reign to a partnership involving Gilbert Gerard, Holcroft's nephew, who was already making a name for himself as a lawyer. In the latter part of Mary's reign, Thomas and Juliana Holcroft did further property deals in London, this time involving Sir Rowland Hill, a former Protestant Lord Mayor of London, as well as Gilbert Dethick, an important Officer of arms and diplomat, and Thomas Leigh, a Protestant businessman and politician from Bedfordshire. Holcroft made his fortune mainly by speculation in monastic lands. Initially he was appointed by Thomas Cromwell to assist the commissioners for the Dissolution of the monasteries in Lancashire. He went on to act as receiver of monastic estates. He then moved into the leasing, purchase, development and resale of lands. He spent a total of £3,798 on monastic estates. As chantries and colleges of secular canons were swept away in a later round of dissolutions, Holcroft served as commissioner for chantries in Cheshire, Lancashire and Chester in 1546, commissioner of goods of churches and fraternities for Cheshire in 1553. He is known to have taken part in the dissolution of the following monastic houses. Holcroft acquired and has kept a reputation for ruthlessness in his acquisition of monastic lands. Robert Southwell, a key figure in the Court of Augmentations, was deputed to Lancashire during 1537, reporting of Holcroft at Furness that: "if there is a good fee Holcroft will take it: he has been diligent, though only put in trust to pluck down the church." Dissolution at some of the larger houses where Holcroft was involved became unusually tortuous and sometimes bloody. The Pilgrimage of Grace, essentially a Yorkshire and Lincolnshire rising, spilled over the Pennines and set off resistance in Lancashire, delaying dissolutions that were already under way. A pardon was proclaimed subsequently for religious who had taken part, and they were ordered to return to their houses for the time being, but not all were covered by this offer and some chose not to take advantage. At Cartmel some of the canons rebelled, possibly provoked by Holcroft