A school in Nottingham, which has taught only boys since it was opened in 1513, welcomes its first intake of girls in its 502-year history today.
Nottingham High School said "much research, thought and careful planning" had gone into the decision to welcome girls.
Today marks the start of the school's first mixed sixth form when 41 girls will join, and there will also be a mixed intake of pupils in Reception, Year 1 and Year 2.
Next September girls will be able to join the school at all ages.
The school said it has "visited and consulted a number of schools that have travelled a similar path" and has "sought advice from professionals to establish sound practice from day one".
While the move to co-education might not sit comfortably with some traditionalists who argue the school should protect its heritage, the decision to welcome girls has been "some time in the making", the school said.
It claims mixed classes will enhance academic standards, with girls adding a "fresh perspective" to classroom discussion. The opportunity to work alongside members of the opposite sex will prepare pupils better for life after school, it added.
Watch Peter Bearne's full report here: