The present Parish was originally part of the Parish of St. James, Clerkenwell.

In 1781, the Prince Regent (later George IV) urged Parliament to provide new churches for the rapidly expanding population of London. In 1822 the Reverend Thomas Handley of the parish of Saint James, Clerkenwell, reported that “the parish contains about 36,000 inhabitants and there is not accommodation in the two parochial churches and chapel for more than one tenth that number.” Mr Handley approached the New River Company which still had ‘uncovered ground’ in the district. “If, in laying out the ground for building purposes you contemplate having a square, I cannot think anything could be more appropriate, both as a necessary and an ornamental edifice, than a handsome church, to be erected in the middle of such a square.” The ground in the centre of the new Myddelton Square was subsequently donated. The New River company appointed it’s surveyor, William Chadwell Mylne, who had laid out the surrounding residences and school, to design the new church and stipulated that there was to be no graveyard around the Church and that the majority of the Square was to be available for the use of the residents. The church foundation stone was laid in April 1825 and the completed church was then consecrated by the Bishop of London, Dr William Howley (later Archbishop of Canterbury) on Tuesday 1st January 1828.

The Church of St Mark cost about £16,000 to build. Today the church is a Grade II listed building, a focal point of The New River Conservation Area, and whose west tower continues to be a handsome and important feature in townscape with commanding views across London. It is floodlit at night. Nicholas Pevsner has described the church as “a neat Gothic box.”

Many changes have taken place to the interior of the Church over the years:
Some re- ordering at the east end took place in 1873 to allow construction of the Vestry and ante-room to the north and the St Mark’s / Lady Chapel to the south. The Side Galleries were taken down during the 1930s as they became unsafe.

Following the Great War 1914 – 1918 the local Finsbury Rifles Regiment erected a lasting memorial to their fallen comrades on the north side of the nave. It carries all their names and the brigade colours. Names of those in the regiment who gave their lives in The Second World War 1939 – 1945 were subsequently added. Poppies are laid and silence observed each year on Remembrance Sunday in their memory.

During the war a barrage balloon broke from it’s moorings and became entangled on one of the pinnacles of the tower. On 21st September 1941 a series of incendiary bombs damaged buildings across the square including the east end of the church. Much of the glass was lost in the blast and the roof partially damaged.

A large part of the Church was closed for several years following the war damage. This necessitated repairs to the roof, removal of the wall plaster, and construction of the present columns and other steelwork to strengthen the roof. During this time the congregation continued to worship regularly in the Chapel with the occasional wedding and larger events being held in the damaged Church. Repair work, together with replacement of the window glass, allowed the Church to return to full use again in 1962 – 21 years after the initial damage!

Removal of the West Gallery, and formation of a Church Hall above the Parish Room and Chapel, took place in the early 1970s.

The London Metropolitan Water Board ( then located in Roseberry Avenue ) commissioned the striking East window to be erected by A.E. Buss of Goddard & Gibbs in 1962. The window depicts the risen glory of Christ ascending. The grey logo of The London Metropolitan Water Board ( now Thames Water ) is central at the base and commemorates the building of the New River, between 1604 and 1613 by Sir Hugh Myddelton. Dame Alice Owen, a great local benefactor, is depicted on the left with the coat of arms of the Corporation of the City of London (who remain patrons of the parish today). To the right is The coat of arms of Finsbury and a picture of the Angel Inn one time first coaching house on leaving the city.

The other windows are unusual in having cast iron tracery, manufactured by the Ironbridge Company, and thought to be the only extant examples in London. Since the early 1970s, St Mark’s has had an unsettled history, with two interregnums, has faced closure, was joined as one Parish with Holy Redeemer (Exmouth Market), with one Priest in charge of both Churches, and has been re-established as a separate Parish with one Priest being Vicar of the two Parishes. In 2013 there was a further short interregnum which concluded with the appointment of a Priest in Charge of the two parishes.

The Millennium was celebrated with a new Church Banner being created out of designs from the congregation. The tree of life on the back has leaves depicting the friends and the families of donors to the project.

Since 2002 we have shared the Church with the World Community for Christian Meditation. This was made possible by converting the Church Hall to Office use, and the Chapel was changed into a Meditation Room. Space was made at the west end of the Church by removing three rows of Pews in order to offset the loss of the Church Hall at first floor level. In 2013 the office was moved into their Meditation Room and the space upstairs developed into a magnificent outreach and training centre, known as Meditatio, which of course includes daily meditation.

Throughout this period, the Congregation had to manage a number of problems with the building fabric, mainly with a deteriorating roof. After ten years of money-raising and several attempts to obtain grants for the renewal of the roof covering, we were successful in being given finance by The Heritage Lottery Fund. This allowed all the roofs to be recovered in 2004 – the roof structure to be put in order, new access stairs and lighting to the Tower to be installed, and the rainwater pipes and drains to be overhauled.

Since this major work, the Congregation has redecorated the Porch and modernised the lighting, the Kitchen in the Parish Room has been totally renewed, and new storage cupboards in the west end of the Church have been constructed. Five artists studios have been created in the crypt along with rented storage space.

In 2004, the Congregation took part in an exercise to consider the re-ordering of the Church. The PCC  discussed this proposal further  during Lent 2008, when the whole congregation studied “Repitching the Tent.” During 2009 a DQI was made involving representatives from the local community in order to embark on a Feasibility Study with a view to increasing space for greater community involvement. This is obviously a long-term project and will involve considerable fund-raising. In 2012  the toilet facilities were improved to include a fully ambulant toilet for the disabled and baby change amentities. The vestry was upgraded at the same time.

In 2008 St Mark’s welcomed Trinity Church Islington, a young, evangelical Anglican community to hold their Sunday worship in the late afternoon and a bible study on Tuesday evenings. They brought many needed skills with them and together with their rent, is enabling several long overdue repairs to be made. More recently Trinity have introduced a Story Corner for mothers and toddlers on Tuesday mornings in term time.

There is a detailed History of St Mark Clerkenwell booklet on sale at the back of the church for £5