Infact Timur Fought Mostly Muslims and Muslims were the worst victims of his atrocities.
And we know all these stuff from his memoriors and not from any other source. But it is also known by historians of pre modern ages all agree to the fact that the facts mentioned in those memoriors were grossly exagerrated to present the kings of those times as some great Destroyer and all Powerfull man on earth whom noone could ever dare to confront!