Samo (c. 600–c. 658) was the founder and sole ruler of the first recorded political union of Slavic tribes, known as Samo's Empire ("realm", "kingdom", or "tribal union"), ruling from 623 until his death in 658. The question about his origins is unresolved. According to Fredegar, Samo was a Frankish merchant from Sens. However, according to Conversio Carantanorum, Samo was of Slavic origin. One of his origin theories suggests that Samo was a Slav who fled persecution in the Frankish lands and sought refuge in Bohemia.
Samo built his career by unifying several Slavic tribes against the robber raiders from the nearby settled Avars and raising a rebellion against Avar rule, showing such bravery and command skills in battle that he was elected "King of the Slavs" (Latin: rex Sclavorum). In 631, Samo successfully defended his realm against the Frankish Kingdom in the three-day Battle of Wogastisburg.