1. Historians like Professor Habib, Dr. Muhammad Nazim and Dr. S. N. Zafar are of the view that the fundamental motive of Mahmood’s invasion on India was to plunder her wealth. Mahmood was not a fanatic and he did not pay attention to the advice of the ulemas. He did not attack the Hindu temples to satisfy his religious zeal but to extract money. The Muslim rulers of Central Asia were also not spared by him. Professor E. B. Havell writes about him that he could have plundered Baghdad, the same way as he looted the cities of India, provided he expected to get wealth from there. His court historian Utbi has also tried to cover his religious zeal with a Iransparcnt cover of greed for gold, whereas historians like V. A. Smith, Dr. Ishwari Prasad and Professor S. R. Sharma are of the opinion that he wanted to propagate Islam in India.
2. From economic point of view the empire of Mahmood was ill straits in comparison to the Indian empire. He was badly in need of money for the proper maintenance of administration, and peace. Money was also much needed for the safety and durability of the empire. He had knowledge about the great wealth of India and the riches stored in Indian temples. He wanted to occupy it.
3. Besides the safety and the proper up-keep of the administration, money was needed for the expansion of the empire. For this he had to wage wars against the Turks and the plunder of India was a good means of acquiring money.
4. Mahmood used to recruit people of martial race in his army and the plunder of India was an incentive for them; therefore, they used to join the army of Mahmood and fought for him. Thus greed for gold tempted Mahmood and his soldiers to make an invasion on India.
5. Some historians do not agree with the above mentioned view. They stress the fact that expansion of Islam was the root cause of this conflict. The court historian Utbi writes that his attacks on India were motivated by the feeling of Jihad for he wanted to convert Darul Herb (Hindu Territory) into Darul Islam (Muslim Territory). Hence he broke up the idols and destroyed the temples. He had already promised the Khalifa that he would do so every year at the time of getting the role of honour and title from him. The Muslim historians affirm that he did not expand Islam but he enhanced its glory. Dr. Nazim has accepted him as a preacher of Islam. In his opinion the victory of Mahmood over Somnath was a wonderful achievement of Islam against the infidels or the idol worshippers and he was praised as ‘The Saviour of Religion’ in the Muslim world.
6. But the modern Muslim historians do not agree that Mahmood wss motivated by religious zeal. Dr. Ishwari Prasad writes that Mahmood wanted to plunder the unlimited wealth of India and after completion of his aim, h: went back to Ghazni. S. M. Jafar opines that Mahmood was not a fanatic; he was a conqueror only.
7. A few historians write a different story about his attack on India. They opine that Mahmood wanted to establish a permanent empire in India. With this aim in view he made successive attacks against Punjab and ultimately assimilated Punjab in his empire. Historians like Gibon, C. V. Vaidya and Nazim, regard him as a successful administrator and politician but the available sources do not confirm this view that he wanted to establish a Muslim empire in India. The following reasons support this view:
1 No doubt he incorporated Punjab into his empire but his aim was to utilize the resources of Punjab for his further victories.
2. Mahmood conquered several places in northern India but he did not incorporate them into his empire except Punjab. In case, he wanted to establish a permanent empire, he should not have committed such a mistake.
3. Mahmood knew it well that it would be difficult to administer the country like India from Ghazni as there was a long distance between the two. Moreover, his own empire was quite extensive and further extension must have created problems for him.
4. The atmosphere and climate of India did not suit the people of Ghazni; therefore, soldiers wanted to go back to their homeland.
5. It was easy to plunder India but very difficult to rule over her and Mahmood never wanted to face such problems as might have shaken his roots.
Despite the reasons quoted above, the invasion of Mahmood was motivated to get elephants from India so that he might make their use against Central Asia. Besides, some historians are of the opinion “that in 999 A.D. Mahmood was recognized Sultan by the Khalifa and he had promised him to invade India.
Apart from being a staunch Sunni, Mahmood Ghazni was very greedy. He did not pay the promised gold Dinars to his court poet Firdausi, the writer of Shahabad. On the one hand his fanaticism goaded him to destroy the temples and idols of the Hindu gods and goddesses while on the other hand his greed and hunger for gold motivated him to plunder the wealth stored in the temples from the days of yore. The way he looted and destroyed the temples of Mathura, Kangra, Thaneshwar and Somnath added to his power and prestige among the Muslims. The later Muslim invaders followed his policy and destroyed Hindu temples and idols and thus immortalized his policy against the infidels.
Mahmood was a man of double-faced personality. He was an idol breaker and destroyer of Arts in India but he was a great lover and patron of arts in Ghazni. He wanted to build some fine monuments in Ghazni for which he required skilled masons and labourers, hence it is opined by some scholars that in order to get fine artisans, he invaded India.