Perpendicular work was introduced early in the fifteenth century, when Roger de Walden, Bishop of London (1405-1406), built a chantry-chapel to the north-east of the choir, and inserted a new clerestory, in the then fashionable style, in place of the original. He also made a considerable alteration in the chancel by substituting a square east-end for the circular apse, part of which was taken down and used as building material for the innovation. But de Walden's work was cut short by his death, when he had scarcely held the See of London for two years, and was buried in his Chapel at St. Bartholomew's, instead of in the Cathedral Church like most of his predecessors.
The Lady Chapel, with the crypt beneath it, dates from about 1410, when also the central tower was probably rebuilt, and decorative additions were made to the Founder's tomb, in the shape of a canopy and panelling. In the first part of the next century Prior Bolton (1505-32) inserted the Oriel window on the southern side of the choir-triforium and the doorway in the south ambulatory, both of which bear his sculptured rebus—a bolt, or arrow, driven through a tun. In 1539 his successor, Robert Fuller, the last of the Augustinian Priors, surrendered the entire property to Henry VIII, in compliance with the Act of Dissolution, its value having been already ascertained in the twenty-sixth year of the King's reign. The exact figures are given by Dugdale as follows:
| Summa | totalis | hujus monasterii. | £773 | 0s. | 1¾d. |
| " | " | reprisarum | £79 | 10s. | 3½d. |
| ———————————————— | |||||
| Et remanet clare | £693 | 9s. | 10¼d. | ||
For many years before the dissolution of the monasteries the system on which they rested had been gradually undermined by the spread of the Reformation, accompanied by a growing conviction that the religious communities had not only outlived their usefulness, and to a great extent departed from the high standard of their founders, but that their enormous wealth had given them an influence far beyond that of any other institution, or combination of institutions, in the kingdom, and brought them into formidable rivalry with the State itself—the more dangerous in proportion to their devoted adherence to the Papacy, with which the State was in collision. By whatever unworthy motives Henry VIII may have been governed in aiming at the monastic property, he was therefore able to bring forward many political considerations, which coincided with those arising out of religious doctrines, to make his measures intelligible to his people, and consequently easy to himself. Among the various plausible reasons which were urged against the continued existence of the conventual houses, one of the most likely to appeal to the practical sense of the multitude was the misuse of the resources with which they had been endowed. While it was admitted that in their earlier days they had been extremely useful in mitigating distress among the poor, it was now argued that their indiscriminate charities were doing more harm than good, and that the changed economic conditions of the sixteenth century called for a corresponding change in the distribution of relief, to save the country from being overrun by undeserving mendicants, amongst whom some of the religious Orders were themselves to be reckoned. It does not appear that any part of this argument held good against the Augustinian Canons, or that the more serious moral charges brought against the smaller communities were at all applicable to their case, which was rather one of involvement in a common ruin than the result of any specific accusation. It is true there are instances of laxity at individual houses, showing a too easy discipline where they occurred, but there is nothing sufficiently extensive or important to compromise the Order as a whole, or materially damage its character in the eyes of the impartial modern student.[10]
It might have been expected that some immunity from the wholesale spoliation which followed the Act would have been granted to Rahere's foundation, in view of his special provision for the poor in the hospital which was an integral part of it. The hospital has indeed been allowed to survive as a separate institution; but the whole of the strictly monastic buildings were doomed, the nave of the church being at once pulled down, and the choir only preserved for the use of the parish. With this reservation, the site of the Priory and the buildings upon it, including the Lady Chapel, were sold in 1546 to Sir Richard Rich, Knight (Attorney General), for the consideration of £1,064 11s. 3d., and the property has remained in the hands of his descendants till quite recent years. The possession was, however, interrupted by Queen Mary, who introduced the Dominican Order of Black Friars into the Convent. They had started rebuilding the nave when the accession of Elizabeth meant a return to the policy of her father, the expulsion of the friars, and the restitution of the Priory estate to Richard (then Lord) Rich and his heirs "in free socage," by a renewal of the previous grant.[11]