An almshouse originally formed part of the great religious houses of the Middle Ages. It was the place where charitable donations were distributed, and in which the hospitality of the house was extended to visitors, including the poor and vagrants as well as pilgrims and other travellers.
St Mary's Hospital has existed on its present site since the end of the thirteenth century; not as part of a religious order but as an independent Christian foundation. A community had already been established to care for the sick, and for the poor who needed a bed for the night. It was supported by endowments and benefactions, and by the middle of the sixteenth century the hospital catered for permanent residents rather than temporary visitors.
The hospital interior is notable for its timber construction, particularly its roof, and for the chapel attached to it. The wooden stalls in the chapel contain some fine misericords, similar to those to be found in the choir at Chichester Cathedral.
Since the beginning of the twentieth century, until early 2018, the Dean and Chapter of Chichester Cathedral were the Trustees of the hospital and its endowments. At that time, the charity's scheme was amended to bring in a number of independent Trustees with relevant experience to take the charity forward, whilst retaining three of the original Cathedral Trustees.
The residential accommodation has been progressively improved and increased. Four cottages were converted into almshouses in 1905 and more recently, these have been converted into three flats plus a guest room; in 1986 the building of St Mary's Lodge provided a further twelve flats, and in 2003 St Mary's Courtyard was completed on land to the north of the medieval building, providing a further six flats, a guest flat, a staff bedsit, as well as office accommodation and a communal meeting room for residents. An additional four flats have also been created in recent years from former staff and rented accommodation.
The Trust also owns a portfolio of residential and commercial properties in and around the City, the rent of which is used to run and maintain the almshouses.