Simplify the following text for a Grade 5 native English-speaking person.
Original: The state of the Gepids was commonly known as Gepidia or Kingdom of the Gepids , whose territory is composed of parts of modern day Romania , Slovakia , Hungary and Serbia .
Simplified: The place where the Gepids lived was called Gepidia or Kingdom of the Gepids . The place where the Gepids used to live contained some of Romania , Hungary and Serbia .