The Conference dates from 1869 when Edward Thring, Headmaster of Uppingham School, asked sixty of his fellow headmasters[2][3] to meet at his house to consider the formation of a "School Society and Annual Conference".

John Dyne (Highgate School) attended on the second day, and Alfred Carver (Dulwich College) did not turn up.

[citation needed] In 2005, the association opened membership to heads of girls-only schools.

An up-to-date list of schools whose Heads are members of HMC can be found on the association's website.

HMC Projects in Central and Eastern Europe is a charity offering opportunities for students and young teachers from Central and Eastern Europe to develop themselves, by coming to HMC member schools in the UK for a year.