In 1398, Timur started his campaign towards Indian subcontinent (Hindustan). At that time the dominant power of subcontinent was Tughlaq dynasty of Delhi Sultanate but it had already been weakened by the formation of regional sultanates and struggle of succession within imperial family. Timur started his journey from Samarkand. He invaded the north Indian subcontinent (present day Pakistan and North India) by crossing the Indus River on September 30, 1398. He was opposed by Ahirs, Gujjars and Jats but Delhi Sultanate did nothing to stop him. The battle between Sultan Nasir-ud-Din Tughlaq allied with Mallu Iqbal and Timur took place on 17 December 1398. Indian forces had war elephants armored with chain mail and poison on their tusks which gave difficult time to Timurid forces as Tatars experienced this first time. But within a passage of time Timur had understood that elephants were easily panicked. He capitalized on the subsequent disruption in the forces of Nasir-ud-Din Tughluq, securing an easy victory. Sultan of Delhi fled with remnants of his forces. Delhi was sacked and left in ruins. After the battle, Timur installed Khizr Khan, the Governor of Multan as the new Sultan of Delhi Sultanate under his suzerainty. Delhi's conquest was one of the greatest victories of Timur, arguably surpassing Darius the Great, Alexander the Great and Genghis Khan because of the harsh conditions of the journey and the achievement of taking down the richest city of the world at the time. Delhi suffered a great loss due to this and took a century to recover.