Okay kiddo, let's talk about a god called Mannus. So, imagine there was a group of people a long, long time ago called the Germanic tribes. They had their own beliefs about the world and gods. One of their main gods was Mannus (pronounced "man-us").
Mannus was believed to be the very first ancestor of all the Germanic people. Just like how you have parents who had parents and grandparents before them, the Germanic people believed they all came from Mannus. They thought he was a really important god because he was the first one in their family tree.
Some people also thought that Mannus may have been a god of war and victory. They believed that if they prayed to him, they would have good luck in battle.
However, we don't really know a lot about Mannus because the Germanic tribes didn't have a written language. We only know about him from stories passed down through generations and from what other people wrote about them later.
Overall, Mannus was important to the Germanic people because he represented their shared ancestry and played a role in their religious and cultural beliefs.