Chormagan simply joined North Persia (presently Iran) to the Tatarian Empire in 629 A.H. Then he advanced towards the territory of Azerbaijan and also joined it to the kingdom.
With those Tatarian victories and the death of Jalaal Ad-Deen in the way we have previously mentioned, the entire region of Persia fell in the hands of the Tatars except for a narrow strip in the west which the Shiite Ishmaelite sect controlled.
It seemed suitable to Chormagan to stabilize himself in this region and stop advancing until he had fortified his forces, got acquainted with the surrounding areas, and taken all measures that would support the Tatarian authority in those territories.

He did that in the period between 629-634 A.H., i.e. throughout five years, during which there was no Muslim revolution against him, nor did a single army move to fight him, although the Muslim armies were filling the areas surrounding Persia and Azerbaijan, i.e. in Iraq, Al-Mawsil, Hijaaz, Egypt, and so on. All Muslims felt that it was not their problem, in so much as it was the problem of the inhabitants of Persia and Azerbaijan, nor was it a general distress befalling all the Muslims. The Muslims of the territories that had not yet suffered from the torment of the Tatars did not realize that they had a duty towards the inhabitants of Persia and Azerbaijan.

They never realized that the turn of killing and destruction would be their lot one day, sooner or later. Moreover, the majority of the Muslims of Iraq, Ash-Shaam, Egypt and Hijaaz were Arabs, whereas the majority of the Muslims of Persia, Azerbaijan and the Eastern part of the state of Khwarezmid were non-Arabs. With the absence of the correct Islamic understanding, and the lack of perfect comprehension of the real foundations on which this religion is based, the Arabs no longer had any sympathy for their non-Arab fellows, and vice versa, as if they were strangers rather than brothers, as stated by Allaah, the Almighty, when He Says (what means): {The believers are but brothers.} [Quran 49:10]

How odious it is that an Arab Muslim comes to have no sympathy for his non-Arab Muslim brother, whether he is Turkish, Afghani, Chechnyan, Indian or Persian. How odious is that which could break the Islamic Ummah, for Islam is not related with a particular ethos, race or color. The only relationship (that links all Muslims) is faith in Allaah the Almighty and His Messenger, sallallaahu ‘alayhi wa salam, and in the religion (of Islam). I mean the relationship of belief, and nothing else other than belief.

It was narrated on the authority of Abu Nadhrah, May Allaah Have mercy upon him, that he said that the Messenger of Allaah, sallallaahu ‘alayhi wa salam, said: "O people! Behold! Your Lord Is One (Allaah)! Your father is one (Aadam)! Behold! There is no superiority of an Arab over a non-Arab, nor for a non-Arab over an Arab (i.e. superiority because of race), nor of a red-complexioned over a black-complexioned, nor of a black-complexioned over a red-complexioned (i.e. superiority because of color) except by virtue of piety." [Ahmad via a Mursal chain of narrators]

https://www.islamstory.com/index.php/en/artical/20754/death-Jalaal Ad-Deen