Final answer:
Clovis I, king of the Franks, was the first important barbarian ruler to convert to Catholicism around 500 CE. His conversion was part of a strategy to foster relationships with the Roman population and other Christian entities, which was a common motive for barbarian leaders seeking legitimacy and integration within Christian societies.
Step-by-step explanation:
The first important barbarian ruler to convert to Catholicism was Clovis I, the king of the Franks. Clovis I's conversion to Catholicism was largely driven by political and practical reasons rather than devout piety. It proved to be a strategic move that facilitated better relationships with the Roman population in Gaul, and also other Christian rulers, as it allowed him to enter into alliances and foster trade.
Clovis converted to Latin Christianity around 500 CE, setting a precedent for other barbarian leaders to follow, as they sought to legitimize their rule and integrate into the network of Christian societies. This conversion was pivotal in establishing a connection between the previously pagan Frankish kingdom and the predominantly Catholic Roman population within Gaul, and it played a significant role in the eventual fusion of Germanic and Roman cultures within the Frankish Empire.
Theodoric the Great, an Arian Christian king of the Ostrogoths, also exemplified the strategic use of Roman traditions and Christianity to rule effectively. Theodoric engaged in diplomacy with other barbarian rulers and respected the religious customs of the Roman populace within his realm, showcasing the complexity and utilization of religious conversion as part of broader political and cultural strategies.