A seal of John Wordsworth, Bishop of Salisbury from 1885 to 1911. On 17th November 1889, the Bishop visited St Mary’s Church in Calne to conduct a Confirmation Service for the town. After the service he went to St Mary’s School and presented it with a document that bears the seal, his signature John Sarum, and the biblical text, 'Whatsoever He saith unto you, do it', which became the motto of St Mary’s. The name Wordsworth was given to one of the dormitories in the old school and later to one at the new school site.
St Mary’s was founded as a church school and had the support of the Diocese of Salisbury from its foundation. It received a financial contribution from the diocese when it bought a property on a new site in 1907, and the Bishop attended the opening ceremony the following year. The Bishop of Salisbury acted as visitor to the school and for many years the Bishop of Sherborne was on the governing body of St Mary’s.
The school’s custom of naming dormitories and buildings after people connected with St Mary’s began in 1889. In addition to Wordsworth, other rooms in the first school were named Duncan, Gabriel and Dunstan. Calne Parish Church stands on the site of an ancient Saxon church at which Dunstan had officiated. An early Archbishop of Canterbury, he was later canonised. One of the four houses which made up the school on The Green was known as St Faith’s and this name was later given to a boarding house that St Mary’s had for a time near the present school site.