Saudi Arabia's King Abdullah has sworn in 30 women to the previously all-male Shura Council, seen by many as a major step in female participation in public life in the conservative kingdom.
It is the first time in country's history that women have been able to hold any political office.
The council advises the government on legislation and comprises 150 members.
Critics say the move is only symbolic, as the council cannot make laws and its members are all appointed by the king.
King Abdullah appeared on state television, welcoming the women at a swearing-in ceremony.
The monarch, seen as a proponent of gradual reform, has also granted women the right to vote and stand in the next municipal elections, scheduled for 2015.
Some Saudi clerics have criticised allowing women onto the Shura Council, saying it was against Sharia (Islamic law).
The king said he had consulted religious scholars, who had approved the move, before he made the appointments in January.
One of the new female council members, Thuraya al-Arrayed, told the BBC it could help reshape opinions of women among Saudis.
"I must say it's an historic occasion. I'm honoured to be part of it. If it works, if it is positive then it will change the attitudes that are still worrying about the participation of women.
"I'm not just talking about the Shura Council, I'm talking about the empowerment of women and their participation in the general affairs of the country," she said.
Despite the latest move, women still have little role in public life in the conservative state.
They are forbidden from driving, are currently excluded from holding high political office. They are also unable to travel without permission from a male guardian and may not mix with unrelated men.