The former head of Carterton community college in Oxfordshire was accused of being verbally aggressive to teachers, disregarding rules for appointing staff and preventing governors from carrying out their duties. He also delivered an end-of-term speech to staff in which he expressed disappointment at them and railed against "smiling assassins" at the school.
Ralph Ullmann, chairman of the hearing, said: "It is difficult to imagine a more intimidating, divisive and demoralising talk to fellow professionals who were about to commence the summer break."
The committee said that while Mr Klee took what seemed like draconian action against staff whom he felt had breached school policies, he excused his own indiscretions by saying they were in the interests of the school.
Among the codes of practice he breached was giving another head information about a teacher which he had not included in the individual's written reference: he described the teacher as an "inveterate shouter" who did not empathise with pupils.
Mr Ullmann said: "Circum-stances may require firm leadership, but this should not be confused with intemperate harshness. Mr Klee's treatment of some members of staff was intimidatory and amounted to bullying."
Mr Klee joined Carterton college in September 1992 and served as head until Oxfordshire council launched an investigation into his conduct. He resigned in October 2003.
Clive Rawlings, representing Mr Klee, said the headteacher had made mistakes because of stress caused by his mother's terminal illness.
Mr Klee, who did not take one day off in nine years as head, said: "The school has enjoyed success as a result of my drive, determination, enthusiasm and leadership."
He admitted making "errors of judgement", but said after the hearing that he was looking forward to returning to the classroom.