Name used by Polish dukes from ruling dynasty. It might not be used by someone outside of ruling dynasty in Middle Ages. Mieszko is most probably a diminutive form of [Miecisław], which (the latter) later was wrongly decoded as [Mieczysław], and this form become popular.
Mieszko is most probably a diminutive form of [Miecisław], which (the latter) later was wrongly decoded as [Mieczysław], and this form become popular.