Valide Sultan (Ottoman Turkish: والده سلطان, literally "Mother Sultan") was the title held by the mother of a ruling Sultan in the Ottoman Empire. The title was first used for the mother of Murat III in the 16th century, superseding the previous title was mehd-i ülya (“cradle of the great”). The Turkish pronunciation of the word Valide is . The title is sometimes translated as Queen Mother, although the position of Valide Sultan was quite different.
The position was perhaps the most important position in the Ottoman Empire after the Sultan himself. As the mother to the Sultan, by Islamic tradition ("A mother's right is God's right"), the Valide Sultan would have a significant influence on the affairs of the Empire. She had great power in the court and her own rooms (always adjacent to her sons) and state staff. In particular during the 17th century, in a period known as the Sultanate of Women, a series of incompetent or child sultans raised the role of the Valide Sultan to new heights.
Nurbanu Sultan was the Venetian-born wife of Selim II, and the mother of Sultan Murad III of the Ottoman Empire and the de facto co-regent as the Valide Sultan in 1574-1583. Nurbanu managed the government together with the Grand Vizier Sokollu Mehmed Pasha and became the first Valide Sultan who acted as co-regent with the sultan during the Sultanate of Women. The most powerful of all Valide Sultans and Haseki Sultans in the history of the Ottoman Empire was Kösem Sultan.
Harem women who were slaves were never formally married to the sultans. Nevertheless, their children were considered fully legitimate under Islamic law if recognized by the father. During the empire's early years, the Ottomans often used dynastic intermarriage to consolidate or extend their power. The last known case of an Ottoman ruler marrying into another dynasty was that of 15th-century sultan Bayezid II, who married Gülbahar Sultan, the daughter of the ruler of the Dulkadir dynasty.