His brother, Mu'izz al-Din, helped manage and expand the eastern part of the empire (as far as Bengal) and served Ghiyath with utmost loyalty and deference.

Ghiyath was born in 1140 CE;[1] he was the son of Baha al-Din Sam I, who briefly reigned as king of the Ghurid dynasty in 1149.

However, this was not the end of Ghurid family disputes; Ghiyath was soon challenged by his uncle Fakhr al-Din Masud, who claimed the throne for himself and had allied with Yildiz, the Seljuq governor of Herat and Balkh.

Shortly thereafter, the ruler of Sistan, Taj al-Din Harb ibn Muhammad, acknowledged the sovereignty of Ghiyath, and so did the Oghuz Turks controlling Kirman.

[6] During the same period, the Khwarazmian prince Sultan Shah, who had been expelled from Khwarezm by his brother Tekish, took refuge in Ghor and requested military aid from Ghiyath.

[4][7] With the aid of the rulers of Bamiyan, Sistan, and his brother Mu'izz al-Din, Ghiyath then defeated the forces of Sultan Shah at Marw al-Rudh in 1190.

Once they had captured Nishapur, Mu'izz al-Din was sent on an expedition towards Ray, but he let his troops get out of control and got little further than Gurgan, earning criticism from Ghiyath which led to the only reported quarrel between the brothers.