The building we now know as St Mark's Coptic Orthodox Church was formerly known as St John's Presbyterian church. Its architect was J N McCulloch, an austere Scot, the building cost £6,000 and it was opened in 1863. It had a very plain interior with bare walls, plain pews, a wooden floor and no organ which disappointed many as it gave 'a sense of depression'. Many changes were made in the ensuing years to improve the aesthetic and practical features including adding galleries for more seating, replacing the floor and installing an organ.
St John's was badly damaged during an air raid in September 1940. The congregation joined their neighbours in Allen Street at the Kensington Chapel until that too was hit. Both congregations did return to their original buildings but eventually joined together under the umbrella of the United Reformed Church.
During its last years as an independent church, St John's became known for a number of things. It staged an experimental religious drama, The Man Born to be King by Dorothy Sayers which, though controversial at the time because an actor depicted Christ, enjoyed success later on the radio. St John's also staged shows by popular entertainers in the 1950s and 1960s. However it will probably be most remembered for the young organist John Tavener whom it appointed in 1952. His work for the funeral of Princess Diana made his name known outside of the Church and has also done a lot to encourage the popularity of medieval liturgical singing. John Tavener stayed at St John's till 1973.
In 1975, St John's, Scarsdale Villas was sold to the Coptic Orthodox Church and has been home to the congregation of St Mark's ever since.