It is now also known as the Royal Garrison Church and is an English Heritage property and a Grade II listed building.

[1] The hospice was established by Peter des Roches (sometimes wrongly named as de Rupibus), Bishop of Winchester and William of Wrotham in around 1212 A.D.[1][2] In 1450 an unpopular advisor to the king, Bishop Adam Moleyns of Chichester was conducting a service at the chapel of Domus Dei when a number of naval seamen (resentful of being only partially paid and only provided with limited provisions) burst into the church, dragged out the bishop and murdered him.

[3] As a result of this the entire town of Portsmouth was placed under the Greater Excommunication, an interdict which lasted until 1508, removed at the request of Bishop Foxe of Winchester.

Once again, the Church fell into disrepair and in 1865 a new restoration project began under the direction of G. E. Street which lasted ten years.

[2] In October 2021, the building was one of 142 sites across England to receive part of a £35-million grant from the government's Culture Recovery Fund.