Dictionary of Medieval Names
from European Sources

Zwentibold m. A Latinization of Old Church Slavic Свѧтопълкъ, from Slavic svet, sviat, from Proto-Slavic *světъ, from Proto-Indo-European *ḱweytos 'bright, shine' + Polish pułk 'regiment'. The Latin spelling of the deuterotheme was influenced by Old High German bald 'bold'.

The name of two 9th C rulers of Moravia, a 9th C king of Lotharingia and saint, two 11th C grand princes of Kiev, and a 12th C duke of Bohemia.

Germany
Latin
896 Zuentebolcho (abl) quix-vol1 6, Zuentebolchus (nom) ibid. 6, Zuenteboldi (gen) ibid. 6; 897 Zuenceboldi (gen) ibid. 7, Zuendeboldus (nom) ibid. 7; 910 Zuendiboldus (nom) ibid. 9
Sweden
Latin
1350 Suantæpolx (gen) SDHK no. 6038
Cite as: J. Uckelman, S.L. Uckelman. "Zwentibold". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Zwentibold.