Carloman of Bavaria in the context of Regnum Italicum

Charles the Fat (839 – 13 January 888) was the emperor of the Carolingian Empire from 881 to 887. A member of the Carolingian dynasty, Charles was the youngest son of Louis the German and Hemma, and a great-grandson of Charlemagne. He was the last Carolingian emperor of legitimate birth and the last to rule a united kingdom of the Franks.

Over his lifetime, Charles became ruler of the various kingdoms of Charlemagne's former empire. Granted lordship over Alamannia in 876, following the division of East Francia, he succeeded to the Italian throne upon the abdication of his older brother Carloman of Bavaria who had been incapacitated by a stroke. Crowned emperor in 881 by Pope John VIII, his succession to the territories of his brother Louis the Younger (Saxony and Bavaria) the following year reunited the kingdom of East Francia. Upon the death of his cousin Carloman II in 884, he inherited all of West Francia, thus reuniting the entire Carolingian Empire.

Louis the Younger (830/835 – 20 January 882), sometimes called Louis the Saxon or Louis III, was the second of three sons of king Louis the German and queen Hemma, with his brothers being the elder Carloman and younger Charles. They all succeeded their father as kings in Eastern Francia on 28 August 876, in accordance with the prearranged partition, with Carloman ruling over Bavaria and the Pannonian March, Louis over Franconia, Saxony and Thuringia, and Charles over Alamannia. Louis and Charles also jointly ruled over eastern parts of Lotharingia. In 879-880, Louis acquired the western part of Lotharingia. In 880, Carloman died and his realm was inherited by Louis. By 881, the youngest brother Charles secured rule over Italy, and was crowned as emperor. Louis died in 882, without legitimate descendants, and was succeeded in all his territories, which encompassed most of East Francia, by his brother Charles.

Domagoj (Latin: Domagoi) was Duke of Croatia from 864 to 876, and the founder of the Domagojević dynasty. He usurped the Croatian throne after the death of Trpimir I and expelled his sons. He took a more active role in the Adriatic Sea than his predecessors, encouraged the use of force and waged many wars, specifically with the Arabs, Venice and the East Francia. Domagoj's belligerence and the tolerance and support of piracy caused bad relations with Pope John VIII, which was further worsened after Domagoj showed no mercy to his conspirators. Formally a Frankish vassal, he used to his advantage the Frankish succession crisis and started a successful revolt against Carloman of Bavaria. After his death in 876, Domagoj was succeeded by his son who was deposed and expelled by Zdeslav in 878.