Simeon I of Bulgaria
The Magyars, settled in the Pontic-Caspian steppe by the 830s, began a westward migration after their defeat by a coalition of Pechenegs and Bulgarians in about 895. They crossed the Carpathian Mountains, invading the surrounding area. Gelou is a local ruler described in the "Gesta Hungarorum" as an opponent of the invading Magyars. Anonymus did not write about Simeon I of Bulgaria, Svatopluk I of Moravia or other opponents known from contemporary sources, instead chronicling Magyar battles with local rulers (including Gelou, Menumorut and Salan) not mentioned in other primary sources.