When Elizabeth became Queen, Day was back in business printing Reformation literature, including all the sermons of the martyr Hugh Latimer, Protestant catechisms, and various works of Continental theologians, and some scientific works. The high quality of his paper, woodcuts and binding earned him a royal patent to print a particular work “for life,” securing his reputation as a master-printer. He also published Psalters, so vital to worship in all the Protestant Churches and homes, and Bible portions, affordable for the poor.
John Day’s crowning achievement, the one that secured his place in history, was the one he undertook in 1563—John Foxe’s Acts and Monuments, better known as Foxe’s Book of Martyrs. That international best-seller enabled Day to move to even larger quarters. He invested his own money in the project, and also interviewed men who had been persecuted or had known the martyrs, as he himself had. The second edition in 1570 ran to 2,300 pages in two folio volumes. William Cecil, the Queen’s main counsellor ordered every cathedral to own a copy. Collectors’ prices of the Second Edition today start at $15,000.