Altan Telgey is a term that refers to the Golden Horde, which was a big group of people who lived a long time ago in what is now Russia and some other nearby countries. Altan Telgey means "Golden Horde" in Mongolian, which is a language that they spoke.
The Golden Horde was made up of nomads, which meant that they didn't have one place that they called home. They moved around a lot with their animals, which were usually horses, cows, sheep, and goats. They were also really good at horseback riding and using bows and arrows.
The Golden Horde was led by a person called a khan, who was kind of like a king. Genghis Khan was the first khan of the Golden Horde, but there were many others after him.
The Golden Horde was really important because they helped spread culture and ideas between different parts of the world. They also traded with other groups of people and made alliances with other countries.
Overall, Altan Telgey was an important part of history and a big group of people who lived a long time ago in a different part of the world.