[1] According to earlier sources, Doubravka urged her husband Mieszko I of Poland to accept baptism in 966, the year after their marriage.

Modern historians believe, however, that the change of religion by Mieszko was one of the points discussed in the Polish-Bohemian agreement concluded soon before his marriage with Doubravka.

The only indication is communicated by the chronicler Cosmas of Prague, who stated that the Bohemian princess at the time of her marriage with Mieszko I was an old woman.

Some researchers have taken up speculative views, such as Jerzy Strzelczyk, who assumed that in the light of contemporary concepts and habits of marriage of that time (when as a rule marriages were contracted with teenage girls) is assumed that Doubravka had passed her early youth, so, it's probable that she was in her late teens or twenties.

In 1895 Oswald Balzer refuted reports that previous to her marriage with Mieszko I, Doubravka was married to Gunther, Margrave of Merseburg and they had a son, Gunzelin.

He wrote that the Bohemian princess tried to persuade her husband to accept Christianity (even at the cost of breaking their marriage and with it the Polish-Bohemian alliance).

Modern historians agree that the baptism of Mieszko I was dictated by political benefits and should not be attributed to any action of Doubravka.

Also, a theory has been advanced (apparently recorded by Thietmar of Prague and supported by Oswald Balzer in 1895) that Vladivoj (c. 981 – January 1003), who ruled as duke of Bohemia from 1002 until 1003, was another son of Doubravka and Mieszko I.

"[13] A similar view of Doubravka's burial place was expressed earlier, in 1843, by Edward Raczyński in his study Wspomnienia Wielkopolski to jest województw poznańskiego, kaliskiego i gnieźnieńskiego (Memories of the Greater Poland districts of Poznań, Kalisz and Gniezno).