The successors of Mahmud were not as capable as him and were engaged in endless wars amongst themselves. Thus, for one century India was spared of the Muslim attacks. But towards the end of the 12th century, Mohammed Ghori, the ruler of Ghor, a small principality in Afghanistan, attacked India and laid the foundation of the Muslim rule in India. In 1175, he invaded Multan and captured it. He then marched towards Gujarat but Raja Bhimadeva gave him a crushing defeat. Later, he conquered Punjab and Sind.
In A.D. 1191, Mohammed Ghori marched against Prithviraj Chauhan, the ruler of Delhi and Ajmer. A fierce battle was fought on the battlefield of Tarain. Prithviraj defeated Ghori. Ghori was wounded severely and was carried away from the field.
But Ghori never forgot his defeat and the next year, in A.D. 1192, he once again marched against Prithviraj Chauhan at the invitation of Jaichandra of Kanauj. Once again the two armies met at the historic battlefield of Tarain. About 150 Rajput chiefs supported Prithviraj. In the beginning, the Hindus had the upper hand but they were ultimately defeated and Prithviraj was slain treacherously. Thus, Delhi passed into the hands of the Muslims. Ghori appointed his slave, Aibak as the governor of Delhi. Aibak conquered Mathura, Gwalior, Meerut and Malwa for his master. His other general, Bakhtiyar Khilji, conquered Bengal and Bihar in A.D. 1202-1203.
Jaichandra of Kanauj, too, was not spared and was killed by the Muslims. After this Ghori returned to Ghor. But he had to come back, as there were rebellions in his Indian territories and some of his governors asserted their independence. He came to suppress the revolt of the Khokans but was slain by them in A.D. 1206. As he had no son, his Indian territories were placed under the charge of Governors. Soon the governors asserted independence. Four of his governors, Yaldoz in Afghanistan, Qubacha in Punjab, Mohammed Bhakhtiyar in Bengal and Qutbuddin Aibak in Delhi struggled for power. Out of these Aibak emerged victorious.
Mohammed Ghori as the real founder of the Muslim rule:
Although Mohammad Ghori cannot be regarded as great a conqueror as Ghazani, there is no denying the fact that he was the real founder of Muslim rule in India. Mahmud raided India only for its wealth but Ghori ame to India with the purpose of establishing a permanent empire here. Ghazni did not annex any conquered territory to his empire, while Ghori annexed to his empire whatever he conquered. It was with this aim that he appointed his generals to look after his conquered territories.