The Mongol invasions of India hand far-reaching effects. Some portions of India territory were temporarily lost by the Delhi Sultan.
The political frontiers of India receded from the base of the Hindukush to the banks of the River Ravi or Beas in the North and the lower course of the river Indus in the South. Most of Sindh and the region between the Ravi and the Indus were under the Control of the Mongols.
The Mongol invasions also hampered the process of expansion and consolidation of the Delhi Sultanate.
The danger from Mongol invasions did not leave the Sultans any time to attend to the task of conquering other parts of India. The rules of Malwa and Rajputana continued to challenge the Sultans of Delhi. The pockets of Hindus resistance in the Doab could not be successfully liquidated in spite of many efforts.
Another effect of Mongol invasions was that the central authority of the Delhi Sultans remained weak. The Sultans had to depend upon the nobles to fight against the Mongols and consequently they could not afford to take action against them.
The Sultans knew that their very existence may be threatened if they decided to take action against those who alone could be expected to support them. Although it was realised that the Iqtadari system resulted in strengthening the hands of the nobles, yet the same was not abolished on account of fear of opposition from the nobles.
The Sultans were forced to give considerable power to their commanders who were appointed to guard the frontiers against the Mongols. It is significant to note that the two dynasties of the Sultans of Delhi, viz., Khajli and Tughluq, were founded by military officials who were Wardens of the Western Marches. As the nobles were very strong, the authority of the Central Government was bound to be weak.
The Mongols invasions also had their effect on the administrative set-up of the Sultans of Delhi. The danger of the Mongols was always there. All the efforts of the Sultans were to protect their kingdom from their attacks. No wonder, the distractive set-up of the Sultan was to be such which could meet the Mongols threat. The result was that the military aspect of the administration was given foremost attention and its civil aspect was practically neglected.
The administration of Sultans retained the form of military occupation rather than that of a settled Government. Before Ala-ud-Din introduced his land-revenue system, there was no revenue organisation worth the name. The collection of revenue was left to the free will of the individual officers who either utilised local agencies like the village headmen or resorted to punitive measures. As there was a continued military emergency facing the Sultans, they were not able to devote themselves to the all-important problem of civil administration whose success alone could ensure the welfare of the people.
In the economic field also, the Mongol invasions had very unhappy consequences. The Mongols isolated India from the rest of Central Asia. They dried up the traditional overland trade routes. A lot of money had to be collected to fight against the Mongols and that could be had by taxing the people more and more. All this must have affected adversely the condition of the people.
The market regulations of Ala-ud-Din imposed an additional burden on the peasantry as they were compelled to sell their commodities cheap. If the Mongols invasions brought evil consequences in their wake, they also brought certain benefits to India. The Mongols conquered Afghanistan and Iran and thereby isolated the Sultans of Delhi from the rest of the Muslim world. The result was that the Sultans of Delhi could not rely upon any help from the Muslims in other parts of the world. Consequently, they were forced to think in terms of India alone. They did not treat their Indian possession as colonies.
The Muslims of India were compelled to make India their homeland and ultimately they absorbed and adopted the traditions of India. Their political and cultural out-look and also their institutions became more and more Indianised. It is rightly said that the Mongol invasions contributed to the slow but gradual process of Indianisation of the alien Muslim conquerors of India.
Another advantage which India derived from the Mongol invasions was that art and culture developed under the Sultans of Delhi. The Mongols had destroyed all the important carters of Islamic culture and learning. Delhi was the only place which could give refuge to all those who wanted scope for the development of their talents.
The result was that many saints, scholars, artists and artisans, famous for their achievements in various fields, flocked to Delhi and Delhi became one of the largest cities of the world. Barani has rightly pointed out that Delhi became “the equal of Baghdad and the rival of Cairo and Constantinople.”