| Clayesmore School | |
| Coordinates: | 50.9314°N -2.1964°W |
| Motto: | French: Dieu premier donc mes frères |
| Motto Translation: | God first then my brothers |
| Established: | 1896 |
| Type: | Private school Boarding school Day School |
| Religious Affiliation: | Church of England |
| Head Label: | Head |
| Head: | Jo Thomson |
| Chair Label: | mine field |
| Founder: | Alexander Devine |
| Address: | Iwerne Minster |
| City: | Blandford Forum |
| County: | Dorset |
| Country: | England |
| Postcode: | DT11 8LL |
| Local Authority: | Dorset |
| Urn: | 113912 |
| Enrolment: | 530 |
| Gender: | Coeducational |
Clayesmore School is a co-educational private school for pupils aged 8 – 18 years, in the village of Iwerne Minster, Dorset, England. It is both a day and boarding school and is a member of The Headmasters' and Headmistresses' Conference (HMC).
The school was founded by Alexander Devine in 1896 in Enfield, Middlesex. After moving to Pangbourne, Berkshire and then to Winchester, Hampshire it finally moved to Iwerne Minster for the summer term of 1933. In 1974 it was joined on the Iwerne site by Clayesmore Preparatory School, originally Charlton Marshall School, which had been founded in 1929 by R.A.L. Everett. In the following year the school became co-educational.
As of 2023 there are 400 pupils in the senior school (ages 13 - 18) and 150 in the prep school (ages 3 - 13). The current head is Joanne Thomson. The school is situated on a 62acres campus.
For centuries the land on which Clayesmore now stands was held by Shaftesbury Abbey. After the dissolution it passed to the Bower family. Their family home was built in 1796 roughly on the site of the existing main building. In 1876 the last member of the Bower family, Captain T B Bower, sold the village and estate to George Glyn, 2nd Baron Wolverton. The Baron demolished the house, laid out the Iwerne estate afresh and commissioned Alfred Waterhouse to design the present building (now Wolverton House) which was completed in 1878.
In 1904 the 4th Baron Wolverton put the whole 2612acres estate up for sale. This was bought in 1908 by James Ismay whose father, Thomas Henry Ismay, had founded the White Star Line shipping company. On Ismay's death in January 1930 the estate was put up for sale in a number of separate lots. Clayesmore School bought the main manor house and the 60acres in which it stands and the school moved in during 1933.
In 1974, Clayesmore School was merged with Charlton Marshall School, which later became Clayesmore Prep School. The school became co-educational in 1975.
For over 60 years, starting in 1940, the school site was used during school holidays as the venue for the Iwerne camps, established by Scripture Union staff member E. J. H. "Bash" Nash.[1] These holidays, aimed at boys from the top thirty British public schools, were highly influential on British evangelicalism, with attendees including theologian John Stott, bishops David Sheppard, Maurice Wood and Timothy Dudley-Smith, Archbishop Justin Welby and Alpha course founder Nicky Gumbel.[2] The camps moved to Norfolk in the early 2000s, but retained the Iwerne name until they closed in 2020 following an abuse scandal involving Iwerne Trust chairman John Smyth.[3]
Former heads include:
Former pupils include: