Any baptised woman is now allowed to head most Vatican departments under Pope Francis' new church reforms.

Under the 54-page constitution, called Praedicate Evangelium (Preach the Gospel) any baptised lay catholic will be allowed to lead departments following centuries of exclusively male leadership.

Francis announced the changes on the nineth anniversary of his installation as Pope.

In the preamble, it says  "The Pope, bishops and other ordained ministers are not the only evangelisers in the Church", adding that lay men and women "should have roles of government and responsibility" in the central administration, known as the Curia.

It continues: "Any member of the faithful can head a dicastery (Curia department) or organism" if the Pope appoints them.

The new constitution also gives new relevance to the role of laity calling it “essential” to the Vatican because of their familiarity with “social reality”.

Pope Francis had already given Vatican departments to lay people, including women.

Last year, Sister Raffaella Petrini became the highest-ranking woman in the world's smallest state after the Pope appointed her to the number two position in the governorship of Vatican City.

Sister Alessandra Smerilli was also appointed to the interim position of secretary of the Vatican's development office, which is responsible for justice and peace issues.

Francis’ constitution replaces the founding constitution "Pastor Bonus" penned by St. John Paul II in 1988 and will come into force from 5th June.