The Ghaznavide Empire established by Mahmud Ghazni could not survive for long and crumbled down under his weak successors. The main cause which contributed to the decline of the Ghaznavide Empire was as follows:
(1) Lack of farsightedness on the part of Mahmud Gaznavi:
Our significant cause of the downfall the Gaznavid Empire was that Mahmud had paid no attention towards consolidation of administration alongside conquest. Lane-poole has written rightly that Mahmud did not have a creative mind. One does not hear of any institution which Mahmud initiated.
He only tried to maintain external security and order in his empire and never made any plans for organizing and consolidating him empire that is why he left behind him only an uncordinated and disorderly empire. As soon as he breathed him last, the empire started disintegrating.
(2) Absence of any Law of Succession:
There was no definite law of succession in the Gaznavid Empire. Therefore after his death there was constant warfare and intrigues in the region of his successors. They dealt a below to the prestige and stability of the empire.
(3) Incompetent Successors:
Mahmud Gazni had established a rigid military dictatorship. This sort of regime can go on only till one capable and powerful ruler succeeds another. Mahmud’s successors were all incapable sovereigns. All of them were lazy and luxary loving. So they could not stop the advance of the Seljuk Turks and their increasing influence.
(4) Increasing Power of the Seljuk Turks:
Mahmud’s death was followed by the rise of another powerful empire that of Seljuk’s. This empire included Syria, Iran, and Trans-oxiama etc. Thin empire came into conflict with the Gajnavids for control over Khurasan. In a famous battle Gaznavid Mahmud was badly defeated and bled for refuge to Lahore. Next Gaznavi Sultan Bahram became a puppet in the hands of the Seljuk’s. Actually it was because of the Seljuk’s that the Gaznavid influence became confined only to Gazni and Punjab.
(5) Rise of the Kingdom of Gor:
Gor was situated between Gazni and heart. This small kingdom presented a big danger to the declining empire of Gaznavi. In 1155th ruler Slauddin Hussain invaded Gazni, plundered it and burnt it to as her. After the shrinking of the Gaznavid empire till Gazni and Punjab only for became all the more sowerful. Muhammad Ghori who had been appointed by him brother as the Ruler of Gazni gradually conquered. The Punjab and in 1192 imprisoned and murdered the Gaznavid Sultan Khusru Malik.