The real founder of the Muslim Empire in India was Muiz-ud-Din Muhammad-bin-Sam, popularly known as “Shihab-ud-Din, Muhammad Ghori or Muhammad of Ghur. It is true that Muhammad-bin-Qasim was the first Muslim invader of India but he failed to carve out a Muslim Empire in India on account of his premature death. Mahmud of Ghazni also failed to set up a Muslim Empire in India and the only permanent effect of his invasions was the annexation of the Punjab. It was left to Muhammad Ghori to build up a Muslim Empire in India on a secure footing.
The district of Ghur is situated in hills between Ghazni and Heart. It was an independent state in the 10th century but its ruler, Muhammad-bin-Suri, was defeated by Mahmud of Ghazni in 1009 A.D. After that, the Rulers of Ghur continued to be the vassals of the Rulers of Ghazni. However, they took advantage of the falling fortunes of the house of Mahmud after 1030 A.D. There were other things which complicated matters.
Under the orders of King Bahram of Ghazni, Malik Qutub-ud-Din Hasan, a Prince of Ghur, was put to death. The result was that Saif-ud-Din Suri, the brother of the deceased, invaded Ghazni and defeated Bahram. Bahram also retaliated and put to death Saif-ud-Din. The result was that Ala-ud-Din Husain the younger brother of Saif-ud-Din; completely destroyed the city of Ghazni in 1155 A.D. Ala-ud-Din also conquered Bemain, Turkistan, Jerun, Bast, Gharjistan and Heart.
It is true that towards the end of his reign he lost Balkh, Turkistan and Herat, but he maintained his hold over other parts of his dominions. He was succeeded by Saif-ud-Din who in turn was succeeded by Ghiyas-ud-Din. Ghiyas-ud-Din recovered Ghazni and put it in the charge of his brother Muhammad Ghori. The latter enjoyed practically complete independence in Ghazni and also treated him as his suzerain.