In 842, the former Duchy of Spoleto, which had been donated to the Papacy by Charlemagne, was resurrected by the Franks to be held against Byzantine catapans to the south, as a Frankish border territory by a dependent margrave.

[2] Although in 876 Guy and his elder brother, Lambert, Duke of Spoleto, had been commissioned by Charles the Bald to accompany Pope John VIII on a trip to Naples in order to break up the alliances that many of the southern Lombard states had made with the Saracens,[3] the family’s interests were generally hostile to the papacy, a policy that Guy initially followed.

At this point, at a diet at Ravenna, the emperor declared him guilty of high treason, and Berengar of Friuli was commanded to strip him of his fief by force.

But because of Odo's coronation that year (888), he turned and went back with designs on the crown of Italy and the emperorship, having won the support of Burgundian nobles such as Anscar of Oscheret.

[citation needed] Fighting between the rival contenders began, and it was Guy who had himself proclaimed king of Italy in a diet held at Pavia at the end of the year 888.

[18] Guy retreated in order to regroup at a fortified place on the Taro and died there suddenly in late autumn, leaving his son under the tutelage of his wife.

Guy's power never extended over much beyond his hereditary lands, which offered a stark illustration of the fact that the imperial title, with its pretensions of universal rule, had by the end of the ninth century become merely a token of the pope's favour, to be fought over by various Italian nobles.