The eyes of Mongols—a great power in Central Asia—were set on the fabulous wealth of India.
They had threatened the security of the northwest of India during the time of Balban also.
Balban proved to be a powerful king and he repulsed their invasions.
During the reign of Ala-ud-Din, their attacks became fiercer as compared to previous ones. Now they had a different object. Earlier, they had invaded India to gain booty and to extend their sphere of influence but now they attacked India to avenge their earlier defeats and also to extend their empire. At times, dissatisfied nobles in the court of the Sultans of Delhi also used to help them.
During the reign of Ala-ud-Din, seven fierce invasions of the Mongols took place but Ala-ud-Din succeeded in defeating Mongols all the times. Ala-ud-Din formulated a strong and a systematic frontier policy. He also planned to fight offensively instead of defensively.
The aggressive policy of Ala-ud-Din made the Mongols fearful of the Indian army. The terror created by Zafar Khan, one of the prominent generals of the Sultan in the minds of the Mongol soldiers was so great that “whenever their horses would not lower their mouths to drink water, the Mongol soldiers would mockingly shout at them whether they had seen Zafar Khan that they feared to stake their thirst.”
Ala-ud-Din followed the measures mentioned below to check the Mongol invasions:
1. Old forts were repaired and experienced troops under the charge of capable officers were posted.
2. New forts were built and put under the charge of seasoned officers and well-trained soldiers.
3. Armament factories were set up and skilled engineers and technicians appointed.
4. A permanent and separate army was prepared for the defence of the North-West Frontier.
5. A special governor was appointed for the North-West Frontier.
6. In the frontier areas of Dipalpur, Samana and Multan, separate armies were stationed.
7. Army was re-organised and its striking power enhanced.
8. Experienced generals like Zafar Khan, Ghazi Malik and Malik Kafur were entrusted the responsibility of defending the border.
Ala-ud-Din’s frontier policy proved very successful. According to Barani and Feristha, not only did the Mongols cease their agressions during the later years of Ala-ud-Din’s reign, but also now they had to defend themselves against the troops of Ala-ud-Din. They have further stated that the governor of the North-West Frontier attacked Kabul, Ghazni and Kandhar and plundered the territories of the Mongols.