Ok kiddo, so way back in the olden days of Europe, there was a big empire called the Carolingian Empire. But when the emperor, Charlemagne, died, his big empire was split up into three parts by his grandsons.
One part was called Middle Francia, and it was in the middle of the other two parts. It was kind of like the middle piece of a sandwich.
Middle Francia wasn't as big or as strong as the other two parts, and it had a hard time staying together. Eventually, it split into even smaller pieces and was taken over by other kingdoms.
But even though it didn't last very long or accomplish as much, Middle Francia was still an important part of Europe's history because it helped shape the way things are today.