The text, however, was never ratified by Nikephoros, as the Royal Frankish Annals, and Charlemagne in a surviving document, explicitly state. The Franks had already subdued the March of Istria in 788, and after overturning the Avar khaganate, they claimed the rich Pannonian plain and the Dalmatian coast; during these events, Slavic prince Vojnomir of Pannonia allied with the Franks.
The text was never ratified by Nikephoros, as historical records from the Frankish Annals and Charlemagne confirm. The Franks had already conquered Istria in 788 and after defeating the Avar Khaganate, they claimed the fertile Pannonian plain and Dalmatian coast. During this period, Slavic prince Vojnomir of Pannonia allied with the Franks.