Wikipedia
Hostivít was the last of the seven Bohemian mythical princes between the (also mythical) founder of the Přemyslid dynasty Přemysl the Ploughman and the first historical prince Bořivoj. The names of the princes were first recorded in Cosmas chronicle and then transmitted into the most of historical books of the 19th century including František Palacký's The History of the Czech Nation in Bohemia and Moravia. According to tradition, he was the father of the non-legendary prince Bořivoj. Some historians suppose that when St. Ludmila was born, Hostivít (or Svatopluk I of Moravia) and Ludmila's father, Slavibor, contracted that Bořivoj and Ludmilla would get married (that can refer to the wedding procession of an unknown bride mentioned in Annales Fuldenses for 871. According to the Chronicle of Dalimil, Hostivít had a brother called Děpolt who inherited the land of Kouřim.
One theory about the number of the princes is propped on the frescoes on the walls of the Rotunda in Znojmo, Moravia but Anežka Merhautová claimed that the frescoes depict all the members of the Přemyslid dynasty including the Moravian junior princes.