By marrying his daughters to sons of the reigning emperor and then engineering timely abdications, a Fujiwara contrived always to be father-in-law, uncle, or grandfather behind the throne.
The Fujiwaras always stayed in power  because they carefully constructed familial marriages and arrangements as to forever have male family at the throne.
A long, narrow corridor lined with shelves (for trays of food) leads to the Courtyard of the Women Servants, from which you enter the Apartments of the Valide Sultan (the sultan's mother, who was the most powerful woman in the Harem).