The former general secretary of the teaching union NASUWT, Eamonn O'Kane, died of cancer at the weekend.
Mr O'Kane was elected general secretary of the union two years ago and continued in the post until shortly before his death.
Announcing his death, the NASUWT's acting general secretary Chris Keates said: "His contribution to NASUWT and the education service has been outstanding. In the tragically short time he was General Secretary he was instrumental in securing the most significant improvements in pay and conditions of service that teachers have received for almost 20 years."
Education Secretary Charles Clarke said that: "The whole of education owes him an immense debt."
"He understood that the future of modern teacher trade unionism lies in partnership and he worked tirelessly to achieve that," Mr Clarke said.
Mr O'Kane was one of the leading proponents of the Government's working time agreement that aims to cut teachers' workloads through employing teaching assistants for routine and administrative work.
He had a political reputation as a moderate - always keen to work with the Government rather than against and was also an advocate of closer relationships between the three main teaching unions, arguing that together they would be a more effective voice for teachers.
The NUT vigorously resisted the working time agreement agreement, but their general secretary still paid tribute to Mr O'Kane.
Doug McAvoy, NUT General Secretary, said: "Eamonn will be sadly missed. He was always a courteous and charming man who worked hard for his union and its members and showed a great deal of courage in the role."