Marianne Clarkson is the Principal of the Kent and Sussex Montessori Centre. Marianne is a state trained teacher, having qualifications and experience in nursery, primary and secondary education. Having qualified initially in the primary - early secondary age range, she later took an education/psychology and music degree in the 0 - 7 year age range, at the Institute of Education, London. She worked extensively with infant children, and held posts of responsibility in the fields of music, and art, craft and display. Before giving up work to have her own five children, she worked with Special Needs Children in a unit attached to a state school, and was successful in seeing some of these children go into mainstream education. Marianne later became a part-time lecturer for the B.Ed. (Hons) Course for Teachers of Children with Special Educational Needs at what is now the University of Greenwich.

Whilst her own children were young, it was through watching and observing them that Marianne became interested in Montessori education, and could see through them Montessori's ideas in action. In 1985 she enrolled on a Montessori Nursery Teaching Course at the London Montessori Centre, and at the end of the course was offered a part-time post, training others to become Montessori teachers, which fitted in with the needs of her family. In 1990, whilst still working under the auspices of the London College, she moved to Chiddingstone and set up the Kent and Sussex Montessori Centre. In 1997 the Centre became an independent organisation for training Montessori Teachers. It is the only U.K. Montessori Centre that has international accreditation and recognition with the Montessori Accreditation Council for Teacher Education, based in the U.S.A. Further information is available on www.macte.org. She is also a member of the Montessori Europe executive committee.

John Clarkson has also worked extensively within the field of education. He holds a M.Ed. in Science Education and Psychology, a B.Sc.(Hons) degree, and also an Open University degree in Educational Administration and Microelectronics. John taught for twenty years in Inner London schools, as Head of Science and also in charge of vocational education and work experience. He has had numerous articles published in scientific and educational journals. Following the closure of the school at which he was teaching, he decided to make a career change and trained as a psychotherapist. More recently he also trained as a Montessori teacher, and now assists Marianne as Registrar at the Kent and Sussex Montessori Centre. He is the managing directore of Montessori Assessment & Education Ltd., and in 2010 he was elected a commissioner on the board of MACTE.