Michal Lutovský writes in his book Bratrovrah a tvůrce státu (Fratricide and country-maker) that only a few coins confirm the existence of Biagota.
These coins are considered the oldest type of Přemyslid denar. An inscription can be read on them, BIAGOTACOIIIIX or BIAGOTACOVIIX, meaning BIAGOTA CONIVNX: wife Biagota. Possibly these coins were made on the occasion of marriage, but there is no proof for it.
It is not even sure that Biagota was the mother of all four adult children of Boleslaus I (Dobrawa, Boleslaus II of Bohemia, Strachkvas and Mlada of Bohemia). Her origins are unclear. She could have originated from one of the German states of the Holy Roman Empire or from a Slavic country (Blahota or Bjegota was an old Bulgarian name). Both hypotheses could be right, corresponding to the contemporary practice of European rulers.
- Compton, N.L.B. (1996). The Family and Direct Ancestors of Herman Everett Compton, 0006-1996. p. 178. Retrieved 9 September 2017.
| Duchess consort of Bohemia
Emma of Melnik