Based on the "Wrath of Khans" podcast, one would be led to believe that the Mongols were completely unparalleled in combat and never lost a battle outside of their tribal feuding. The only mention of a loss comes at the end of the final podcast, a mere footnote about how an overwhelmingly large Mamluk force defeated an undermanned garrison army.
Now, I have no doubt that the Mongols were great warriors and that they were a league above most of their enemies at the time. But the historical skeptic in me couldn't help but raise an eyebrow at the claim that the largest conquest in human history did not face a single defeat. I don't want to discredit Dan Carlin, but I felt like some facts must have been omitted for the sake of the story.
So I'm curious, were the Mongols really so superior to all the other fighters of the time that they never lost a battle, anything from a rout to the loss of an entire force?
No, they certainly were not. Mogol forces were beaten by the Jin, most famously perhaps at Gui'de. Previously they had won tactical victories at Mount Yu and serveral battles surrounding the siege of Zhongdu. The Mogols also suffered very serious casualties in the Chechen and Ingush regions which they were never fully able to conquer. Added to this they suffered several defeats in Europe, especially in the later invasions such as Lagow and Stary Sazc. I know they also suffered defeats in their later invasions of Hungary where large portions of the mongol forces were lost.
So were the Mongols undefeated except through in-fighting? No. Absolutely not.