In theory at least, once someone had become a member of the clergy in the Middle Ages, they remained so for life. Although some people did resign their churches (and some bishops also resigned as did at least one pope) and many rectors and vicars who were elderly, ill or experiencing an impairment continued to hold churches. To help them with their duties, the bishop (or, in the case of York, the archbishop) of the diocese where they worked could appoint a helper, known as a coadjutor, for each minister.
Examples of these could be found under many archbishops of York, including William Melton, who was archbishop during the fourteenth century. Although the original letters appointing coadjutors have not survived, these were sometimes copied into a register of documents issued by the archbishop, and from Melton's register we can see the range of people for whom coadjutors were appointed.
The first of Archbishop Melton's coadjutors for someone with a disability was William de Sutton, appointed in 1322 to help Roger de Sutton, rector of North Collingham, who was paralysed and unable to carry out his duties. Roger is said to have made a request, and given written permission, for such an appointment and the archbishop was careful to safeguard the income of the church. He orders that an inventory of all the church’s and the rector's goods be drawn up and that the coadjutor should render an account whenever asked. A transcript of the inventory can be seen here and a translation here.
In 1326 William de Hundon was appointed to be coadjutor for Elias de Coulton, who was canon of Southwell (and so one of the clerical staff at Southwell Minster), who was described as being almost blind and completely incapacitated. In 1330 Ralph de Hertford, rector of Hockerton, was similarly described as blind and incapacitated when Henry Asselyn was appointed as his coadjutor. A transcript of the document can be seen here and a translation here.
Finally, in 1333, a coadjutor, Robert de Somerhous, was appointed as coadjutor for his brother, John de Somerhous, who was the rector of Rounton and was described as old, totally blind and ill.
Such coadjutors enabled the rector or victor in question to retain and fulfil their position, with the support of the coadjutor’s contribution. Such support enabled the community to receive the same level of support, the rector or vicar to maintain and oversee their role being performed, and the coadjutor to gain experience which may, in some cases, have helped them gain their own ministry.