Okay kiddo, let's talk about the Battle of Tangdao.
So, a long time ago in China, there were two big groups of people: the Mongols and the Chinese. They didn't get along very well and would often fight each other for control of different areas.
One day, the Chinese emperor sent his army to a place called Tangdao to try and stop the Mongols from taking it over. The army had lots of soldiers with weapons like swords, spears, and bows and arrows.
The Mongols also had a big army with lots of soldiers and weapons. They weren't going to let the Chinese take over Tangdao without a fight.
The battle started and there was a lot of fighting between the two groups. The Chinese soldiers were doing well at first, but then the Mongols used a special tactic called a "feigned retreat". This means they pretended to run away, which made the Chinese soldiers think they were winning and started chasing after them.
But the Mongols were clever and had hidden soldiers waiting to attack the Chinese from behind when they got too far into the Mongol's territory. This surprised the Chinese and made them lose the battle.
So in the end, the Mongols won the battle and were able to take control of Tangdao. It's important to remember that battles like this one happened a long time ago and we don't like to fight like this anymore. We always try to find peaceful solutions to our problems!