The church was founded before 1055 by Siward, Earl of Northumbria, and is the earliest known dedication in the world to St Olaf (Olav) (d 1030). Siward was effective ruler of the north of England under the king, and owned the Galmanho estate which included the present St Mary's Abbey precinct. Foundation of a church was a conventional act for any lord in Anglo-Saxon England, and such buildings were not necessarily intended to serve the local population as we think of a parish church today. Nevertheless, the dedication is certainly significant, and the location also of interest since it lies at the junction of Marygate, running from Bootham to the river, and an ancient routeway to the city terminating in what is now Marygate Lane. It is very likely that the church was placed at the entrance to the site of what may have been his principal residence and seat of power, perhaps both for its symbolic importance as well as accessibility. Unfortunately, our direct knowledge is limited to a brief reference in the Anglo-Saxon Chronicle for 1055, to the death and burial of Siward in the minster at Galmanho which he had founded and dedicated to St Olaf, though it is itself very exceptional to have any historical record of a church foundation at this period. Its description as a minster implies a religious community, perhaps a base from which priests went out to minister to local communities or or the earl's lands.
The monastic period
After the conquest the church was given to Alan of Brittany, who after 1080 granted the church and four acres of land to a group of Benedictine monks, led by Stephen, who were part of a larger project to re-establish the monastic tradition in the north of England. They were given permission by the king to found an abbey and were established there by 1086. In 1088 they were granted more land by King William II and building began in 1089 of a new monastic church close by dedicated to St Mary. This was to become one of the great abbeys of medieval England.
We do not know what was included in the original grant of the church and four acres, or the additional land given subsequently, and whether St Olave's was still a functioning church and in what capacity when Stephen and his fellow monks arrived. The impression sometimes given of a group of pious monks chancing on generous benefactors and vacant property is unlikely to be the whole story. It might be that with the establishment of a new secular centre of power over the northern province in the new castle on the other side of the city, what may have been the earlier centre at Galmanho was being turned to religious use on a scale to rival the Minster. The 12th century account of the king personally cutting the first turf for the new church in 1089 would fit with that picture. The grants by Count Alan and the king are conventionally pious acts, but the location should not be overlooked
Quite how St Olave's itself fits into the story is something that remains to be properly explored. In itself, the creation of a new and much larger church alongside it is unsurprising - the site of St Olave's is cramped and it would have been convenient to continue to use the the old church whilst the new was being built. There was nothing unusual in York in one church existing adjacent to or even physically abutting another, because just such a situation existed at the Minster. Architecturally, St Olave's became in time physically incorporated into the abbey fabric. The principal entrance to the abbey grounds must always have been beside the church, and visitors to the Museum Gardens can still see the late 12th century arcading that is part the earliest surviving element in what became a very substantial gatehouse structure. The lower levels of the church tower are part of that as is masonry in the yard between it and the present garden entrance, and included a gate chapel dedicated to St Mary on the upper floor. The north wall of the church is in line with the gatehouse and that part of the abbey walls leading to the river, and after 1266 when work began on a defensive wall around the abbey must have been incorporated into this in some way. To the east of the church, and directly onto Marygate, is a very substantial stone wall that may be part of the abbey almonry, accessible to supplicants but secure against attack. Nevertheless St Olave's retained a separate identity and this became the subject of a bitter and protracted legal dispute in the late 14th and the 15th century. It had an extensive parish and a large endowment income, and the nave had continued to serve the laity. The city argued that it was a parish church, that the condition of the building was ruinous and that the abbey was responsible for maintenance out of the income. This was eventually settled in 1466 with the parochial status of the church confirmed but financial responsibility for the church resting with the laity. A major rebuilding and extension was undertaken, including a tower and bells. All this should not necessarily be taken as proof that the church had no building works since the 11th century or that it was actually in a state of complete disrepair by this time. Many York churches were substantially or wholly rebuilt in the 15th century even if the existing structures were only a century or two old, and it may be that the rebuilding should be seen as essentially one of modernisation.
A continuing parish role
After the dissolution of the abbey in 1539, St Olave's continued as a parish church and in 1586 the parish itself was united with that of St Giles at the end of Gillygate, somewhere in the vicinity of the present Salvation Army citadel. St Giles' church was demolished shortly afterwards. The former abbot’s lodging (now known as the King’s Manor) became the headquarters of the Council of the North, and St Olave’s the Lord President’s parish church. The church formed part of the line of the city defences at the siege of York in 1644, and may have suffered damage when St Mary's Tower on the corner of Bootham and Marygate was blown up and fierce fighting took place on the bowling green east of the church. Some of the dead were buried at the church. The often repeated claim that the church was used as a gun platform depends, however, on a letter written soon after the siege by somebody who evidently did not know the city well. His description of it being used by the Parliamentary army does not fit the history of the siege. Though he might have meant to write Royalist that seems an unlikely error, and more probable is that he confused it with St Lawrence's which was certainly held by the besieging army. Whatever the reasons the church was in need of repair by the beginning of the 18th century and was extensively restored in 1720-1 partly with the use of masonry from the abbey. As the old abbey wall had ceased to have a significant defensive purpose, that work included significant alterations to the north wall of the church with the insertion of large windows into what may previously have been a blind wall. The clerestory was removed and the upper part of the tower rebuilt, so although the style of a 15th century church was retained the external appearance must be very different from that of the 1460s rebuilding.
The 18th century parish population was small, with only 121 families in 1743. But it had grown considerably by the middle of the nineteenth century, as had York as a whole, with the growth of industrial activity being directly consequent on and aided by the railways. The formerly extensive parish was divided up with the creation of St Thomas-in-the-Groves in 1855, Clifton in 1871, and St Luke's Burtonstone Lane being transferred back in 1910 and finally established as a separate parish in 1930. Although largely now swept away, even the remaining parish had extensive areas of poor housing. For example the present Marygate and Bootham Row car parks as well as the narrow strip along Marygate itself between road and abbey walls were occupied in this way. There were many small industrial premises. The church hall on Marygate Lane stands on the site of a tannery. Such challenging social conditions were often the focus for mission charged by High Church zeal combining personal holiness with a strong commitment to service. William Dodsworth, who became vicar in 1892, had such a faith. The chancel had already been extended in 1887 (the church formerly ended in line with the aisles) and further extensions were added to the chancel, a chapel dedicated to the annunciation and the vestry in the period to 1908 giving the church the shape it has today and permitting a liturgical use with music and servers which has continued. Charles Dodsworth was succeeded by Charles Bell, later on to be vicar of St Martin Coney Street and St Helen from 1921 to 1955.
By the end of the 20th century St Olave’s had moved away from serving a largely local population to a city wide mission with a strong focus on liturgical worship within the main stream of liberal anglican thought, and a heavy emphasis upon music in worship.