In this year, Ghiyaath Ad-Deen did his best to establish his power in the territory of Persia, South and West of Iran. But an affliction broke up in this region between him and one of the governors called Sa‘d Ad-Deen ibn Dakla, and resulted in a long fighting between them for the period of that year, which ended with an agreement between both parties that the territories would be divided between them; and there is no strength and no power save in Allaah.

While Ghiyaath Ad-Deen was engaged in fighting with Sa‘d Ad-Deen in the South of Iran, a Tatarian brigade, as small as no more than 3,000 horsemen attacked the city of Rayy and struck its dwellers with the sword and killed as much as they liked, and committed robbery and ruined the city. Then they left it for Sava and did the same.

Then, they moved towards Qum (Ghom, South of Tehran) and Qashan, and destroyed them both, killed their inhabitants and demolished their houses. Then, they betook themselves to Hamedan (or Hamadan) and exterminated its people by killing, captivity and robbery, and ruined the city in the same way as they did with the others. Then, they returned safely to Genghis Khan.
No more than 3,000 Tatars did all we have mentioned above.

Allaah the Almighty made the Tatars seem numerous in the eyes of the Muslims, just as He Made the Muslims seem few in the eyes of the Tatars; and as much as the Tatars grew more awesome in the sight of the Muslims, the Muslims grew more trivial in the sight of the Tatars.

Why? Because the Muslims were preoccupied with their own selves, and could no longer distinguish the enemy from the friend; and although the crises were expected to gather the Muslim row, they divided it. This goes back only to the weakness of faith in the hearts, and the greatness of this world in the eyes, not to mention the bad, if not the lacking, education along the times.

Such moral defects and heart diseases, as expected, resulted in what was mentioned by Ibn Al-Atheer, May Allaah have mercy upon him, in his speech on the incidents of the year 621 A.H., when he said, "In this year, there was shortage of rain in the territories, and even in case it rained, it would fall at intervals too close to be of use in irrigation. This meant that the territories ran short of crops.

Furthermore, the locusts came upon them, and found nothing to eat in the earth but those plants. The locusts came in great swarms, beyond all limits. Consequently, the prices of goods rose in Iraq, Mawsil, and all regions of Diyaar Al-Jazeerah, Diyaar Bakr, and others, not to mention the scarcity of provisions."
What took place of calamities in this year, by virtue of the locusts, famine, shortage of fruits, etc, was expected rather than accidental, as it corresponded to the Divine established norms,.

If a time comes upon the Muslims in which they feel the prices have risen high, the crops have fallen short, the economy has weakened, and the living has become hard, they should then reconsider themselves, and have a pause with themselves for accounting, and compare their behaviors with the principles of the Book of Allaah the Almighty. If they are true to themselves, surely they will discover the disease and know its medicine: {We Have not Neglected in the Register a thing.} [Quran 6:38]

http://300035.dotdothktrade.tech/en/artical/20735/events- 621 A.H.