<P> It is also part of a longer trend predating the spread of Islam . Like other settled, agrarian societies in history, those in the Indian subcontinent have been attacked by nomadic tribes throughout its long history . In evaluating the impact of Islam on the subcontinent, one must note that the northwestern subcontinent was a frequent target of tribes raiding from Central Asia in the pre-Islamic era . In that sense, the Muslim intrusions and later Muslim invasions were not dissimilar to those of the earlier invasions during the 1st millennium . </P> <P> By 962 AD, Hindu and Buddhist kingdoms in South Asia were under a wave of raids from Muslim armies from Central Asia . Among them was Mahmud of Ghazni, the son of a Turkic Mamluk military slave, who raided and plundered kingdoms in north India from east of the Indus river to west of Yamuna river seventeen times between 997 and 1030 . Mahmud of Ghazni raided the treasuries but retracted each time, only extending Islamic rule into western Punjab . </P> <P> The wave of raids on north Indian and western Indian kingdoms by Muslim warlords continued after Mahmud of Ghazni . The raids did not establish or extend permanent boundaries of their Islamic kingdoms . The Ghurid sultan Mu'izz ad - Din Muhammad Ghori, commonly known as Muhammad of Ghor, began a systematic war of expansion into north India in 1173 . He sought to carve out a principality for himself by expanding the Islamic world . Muhammad of Ghor sought a Sunni Islamic kingdom of his own extending east of the Indus river, and he thus laid the foundation for the Muslim kingdom called the Delhi Sultanate . Some historians chronicle the Delhi Sultanate from 1192 due to the presence and geographical claims of Muhammad Ghori in South Asia by that time . </P> <P> Ghori was assassinated in 1206, by Ismāʿīlī Shia Muslims in some accounts or by Hindu Khokhars in others . After the assassination, one of Ghori's slaves (or mamluks, Arabic: مملوك), the Turkic Qutb al - Din Aibak, assumed power, becoming the first Sultan of Delhi . </P>

When did the delhi sultanate lay its foundation