Charles Dormer, the headmaster of Immanuel College in Bushey, is to leave next year after five years in the job.

Edward Misrahi and Anthony Warrens, co-chairmen of the fee-paying Orthodox college, told parents this morning governors were sad to announce the departure after “five years of inspirational leadership”.

Mr Dormer, who previously headed the King’s School in Grantham, said “after a wonderful time I have decided that it is my time to move on”.

While the search for a successor continues, the school’s chief operating officer Martin Blain and Rabbi Eliezer Zobin, who has been newly appointed as principal, will assist Mr Dormer over the transition period.

Mr Misrahi and Professor Warrens said Mr Dormer had led the college “through a period of unprecedented growth and success in all areas of school life”.

In his letter to parents, Mr Dormer, who is due to break the news to pupils this afternoon, said, "When a teacher moves on from a school, children can ask why, and feel at some point some form of loss. We must sometimes help them to understand that people move on in life, and that it is best to celebrate what has been shared.”

The college made the Sunday Times's top 100 English independent schools this year, ranked number 90.