According to Fredegarius, the only contemporary source, Samo was a Frankish merchant[1] who unified several Slavic tribes against robber raids and violence by nearby settled Avars, showing such bravery and command skills in battle that he was elected "King of the Slavs" (Latin: rex Sclavorum).

[2] The interpretation that places the start of Samo's reign in the year of Fredegar's arrival has been questioned on the basis that the Wends would have most likely rebelled after the defeat of the Avar khagan at the First Siege of Constantinople in 626.

[3] Samo went on to secure his throne by marriage into the major Wendish families, wedding at least twelve women and fathering twenty-two sons and fifteen daughters.

The majority of the besieging armies were slaughtered, while the rest of the troops fled, leaving weapons and other equipment lying on the ground.

In the aftermath of the Wendish victory, Samo invaded Frankish Thuringia several times and undertook looting raids there.

Although he was of Frankish origin, Samo demanded that an ambassador (Sicharius) of Dagobert I (King of the Franks) put on Slavic clothes before entering his castle.

A few scholars have attacked the entire account as fictitious, but Fredegar displays a critical attitude and a knowledge of detail that suggest otherwise.

[10] If this is correct, it may explain why he is remarkably free of typical stereotypes of heathen Slavs, and why he was familiar with the Wends as a specifically pagan nation.

[11] He is a major character (in the first few episodes as an amnesiac stranger going by "Vlad") in a Ukrainian-funded series The Slavs which was as of September 2024 available on Amazon Video.