Rustem Pasha was taken as a child to Constantinople (modern-day Istanbul), where he built a military and bureaucratic career under the protection of Hürrem Sultan, Süleyman's favorite and legal wife and Mihrimah's mother.

By the time they graduated, the boys were able to speak, read and write at least three languages, were able to understand the latest developments in science and finance and were able to excel in military leadership as well as in close combat skills.

The mirahur accompanied the Sultan during his travels, so the Süleyman knew Rüstem for a long time before he appointed him – possibly inspired by Hürrem – to be tutor to his sons.

His biggest success was the agreement, signed in 1547, with King Ferdinand I and the Emperor Charles V, which confirmed, without firing a shot, the western border of the Ottoman Empire for more than fourteen years.

The Emperor's ambassador Ogier Ghiselin de Busbecq wrote that Charles tried to revise the unfavourable agreement, several times but that Rüstem always resisted.

Mustafa made the mistake of frequently receiving foreign ambassadors and Ottoman commanders without his father's knowledge, and was regarded by them as an important ally against Süleyman.

Understanding the danger of the situation, Süleyman remembered how his father Selim I had dethroned his grandfather Bayezid II (who was killed only a month after his abdication in 1512).

And so the Rüstem, who had been extolled as the 'pillar of the Ottoman Empire,' as a brilliant economist and a sophisticated statesman, was forgotten along with all his great projects and charitable foundations.

[8] By then Rüstem was already a wealthy man and had, since 1538, a splendid career as Governor of Anatolia, one of the two most important administrative regions in the Ottoman Empire, and a post seen as a stepping-stone on the way to becoming Grand Vizier.

Rüstem and Mihrimah had a daughter, Ayşe Hümaşah Sultan (1541–1598), firstly married in 1557 to Semiz Ahmed Pasha, and at least one son, Sultanzade Osman Bey (1546–1576, buried in his father's türbe, in the Şehzade Mosque).

According to most contemporary testimonies (excluding Taşlıcalı Yahya Bey's Şehzade Mustafa Mersiyesi), he was one of the few state dignitaries who didn't take bribes.

In his will (a part of an endowment charter from 1561), Rüstem left a complete inventory of his property in the hope of securing his great foundation projects after his death.

Most historians emphasise how hard Rüstem worked to consolidate and improve the troubled economy of the Ottoman Empire which had been impoverished by excessive spending on wars and the lavish lifestyle of the court.

Toll-free bridges, roads, covered bazaars, granaries, baths, hospices, caravanserais, convents, schools and various other establishments were built on his lands for the public benefit.

He supported agriculture, founded new trading centres, like the bazaar in Sarajevo, and established silk factories in Bursa and Istanbul, and assorted social and educational institutions.

He developed the domestic economy by encouraging major public works projects such as water distribution systems in Istanbul, Mecca and Jerusalem.

At the time of his death in Constantinople on 10 July 1561, his personal property included 815 plots of land in Rumelia and Anatolia, 476 mills, 1700 slaves, 2,900 war horses, 1,106 camels, 800 gold embroidery Holy Qur'ans, 500 books, 5000 caftans, 130 pieces of armours, 860 gold embroidered swords, 1500 silver tolga (helmets), 1000 silver balls, 33 precious jewels etc.

[11] In the acclaimed Turkish television series Muhteşem Yüzyıl (The Magnificent Century), Rüstem Pasha is portrayed by actor Ozan Güven.