Simplify the following text for a Grade 12 native English-speaking person.
Original: Within East Francia four stem duchies had ( re - ) developed : Swabia ( Alamannia ) , Franconia ( the eastern part of former Austrasia ) , Saxony and Bavaria .
Simplified: East Francia was divided into four duchies : Swabia ( Alamannia ) , Franconia , Saxony and Bavaria ( with Carinthia ) .