Hürrem and Mahidevran had borne Sul

Hürrem and Mahidevran had borne Suleiman many sons, four of whom survived past the 1550s: Mustafa, Selim, Bayezid, and Cihangir. Of these, Mustafa was the eldest and preceded Hürrem's children in the order of succession. Hürrem knew that should Mustafa become Sultan, her own children would be strangled. Yet Mustafa was recognized by many of the people as the most talented of all the brothers and was supported by Pargalı İbrahim Pasha, who became Suleiman's Grand Vizier in 1523. A number of sources[which?] have suggested that Ibrahim Pasha had been a victim of Hürrem Sultan's intrigues and rising influence on the sovereign, especially in view of Ibrahim's past support for the cause of Şehzade Mustafa. Hürrem is usually held at least partly responsible for the intrigues in nominating a successor. Although she was Suleiman's wife, she exercised no official public role. This did not, however, prevent Hürrem from wielding powerful political influence. Since the Empire lacked, until the reign of Ahmed I, any formal means of nominating a successor, successions usually involved the death of competing princes in order to avert civil unrest and rebellions. In attempting to avoid the execution of her sons, Hürrem used her influence to eliminate those who supported Mustafa's accession to the throne.[17]

Thus in power struggles apparently instigated by Hürrem,[18] Suleiman had Ibrahim murdered in 1536 and replaced with her sympathetic son-in-law, Rüstem Pasha (Grand Vizier 1544-1553 and 1555-1561), the husband of her daughter by Suleiman, Mihrimah Sultan. Many years later, towards the end of Suleiman's long reign, the rivalry between his sons became evident. Furthermore, both Hürrem Sultan and the grand vizier Rüstem Pasha helped turn Suleiman against Mustafa and Mustafa was accused of causing unrest. During the campaign against Safavid Persia in 1553, because of a fear of rebellion, Sultan Suleiman ordered the execution of Mustafa.[19] According to a source he was executed that very year on charges of planning to dethrone his father; his guilt for the treason of which he was accused remains neither proven nor disproven.[20] After the death of Mustafa, Mahidevran lost her status in the palace (as the mother of the heir apparent) and moved to Bursa and lived a troubled life.[15] She did not spend her last years in poverty, however, for her stepson Selim II, the new sultan after 1566, put her on a salary.[20] Her rehabilitation may have been possible only after the death of Hürrem in 1558.[20] Cihangir, Hürrem's youngest child, allegedly died of grief a few months after the news of his half-brother's murder.[21]

After Suleiman executed Mustafa in October 1553 a degree of dissatisfaction and unrest arose among soldiers who blamed Rüstem Pasha for Mustafa's death. Then Suleiman dimissed Rüstem Pasha and appointed Kara Ahmed Pasha as his grand vizier in October 1553. But almost two years later, Kara Ahmed Pasha became the victim of vicious calumnies brought against him by Hürrem Sultan, who wanted her son-in-law, Rüstem Pasha, to become the grand vizier again. Kara Ahmed Pasha was strangled in September 1555, and Rüstem Pasha became the grand vizier (1555-1561) once more.

Suleiman also allowed Hürrem Sultan to remain with him at court for the rest of her life, breaking another tradition—that when imperial heirs came of age, they would be sent along with the imperial concubine who bore them to govern remote provinces of the Empire; the concubines were never to return unless their progeny succeeded to the throne (Sanjak Beyliği).[22] Hürrem also acted as Suleiman's advisor on matters of state, and seems to have had an influence upon foreign affairs and on international politics.[7] Two of her letters to King Sigismundus II Augustus of Poland (reigned 1548-1572) have survived, and during her lifetime the Ottoman Empire generally had peaceful relations with the Polish state within a Polish–Ottoman alliance.