Originally founded c1055 as a Benedictine abbey dedicted to St Olave, the monastery was re-sited in 1088 by William II and became known as St Mary's Abbey, York. It eventually became the largest and wealthiest Benedictine house in the North of England.
The first church, a Norman structure with an apsidal east end, has long since disappeared, and there are only fragmentary remains of the replacement church begun in 1270. As a symbol of St Mary's Abbey financial standing, the new church was built on a much larger scale, and in the lavish styles of geometrical Gothic, and early Decorated. Few examples of the quality and beauty of this architecture have survived, but some sections at the west end, and in the north transept are worth a closer investigation. The north aisle wall remains standing to a good height and shows some of the splendid arcading that once adorned the internal walls of the church.
Only scant details are known about the claustral buildings but it would seem that they were first completed during the late 12th century, with much of the south range being rebuilt some 200 years later. Other monastic buildings at St Mary's Abbey have survived to a much better degree. The old Abbot's House, the 14th century timber-framed guest house, and the Norman gatehouse remain virtually intact. After the Dissolution in 1539 St Mary's Abbey became Crown property, some of the these buildings being utilised as administrative offices, and later for educational purposes.
Today the site is run as a museum and gardens. The ruins of the abbey church now provide the main feature of the public park, but the remains of the medieval Chapter House are preserved beneath the early 19th century museum itself. From the gatehouse entrance, long stretches of St Mary's Abbey outer precinct walls can be followed until they join the City walls. Although there is not much evidence of this once great abbey, the quality of the ruins invoke a real sense of loss - had they survived what grandeur might today's visitor be witnessing.