Britain's Royal Air Force (RAF) on Friday became the first branch of the military to open every role to female service personnel.
The move follows a landmark decision by the UK government last year to lift the ban on women serving in combat roles in the British Army.
From today, even women can apply to join the RAF Regiment, its ground-fighting force.
"A diverse force is a more operationally effective force.
Individuals who are capable of meeting the standards for the regiment will be given the opportunity to serve, regardless of their gender," said UK defence secretary Michael Fallon.
The main role of the 2,000-strong RAF Regiment is to patrol and protect RAF bases and airfields.
Women have already been allowed to serve in close combat roles in the Royal Armoured Corps, but it will be another year before they can seek to enter the Royal Marines, which has tougher physical demands.
The ban on women fighting in combat roles was lifted in 2016 under the David Cameron led government.
In July, Fallon had announced that the RAF Regiment would be open to them from September this year - ahead of an original 2018 schedule.
