All roles in the series are played by non-professional actors. Most leading roles are played by crew members.
"Croatian Kings" is the best-selling product of Croatian Radiotelevision ever. It has been viewed in more than 30 European countries.
Stories of seven medieval Croatian peasants, placed in the middle of every episode, were not in the original screenplay. During filming in Zagvozd, some of crew members, bored in the pause between two filmings, put medieval costumes and convinced make-up artists to change their faces into primitive medieval look. When director and writer Domagoj Buric saw them, he immediately had an idea for story of seven peasants. This can be seen in making-off movie, attached to DVD edition of the series.
Nine languages are used in the series: modern Croatian, ancient Croatian, English, French, German, Latin, Greek, Czech and Polish.
After finishing filming the opening scene of 6th episode, the coronation of king Zvonimir, director and editor found out that large light unit left visible at the corner. It took one week for series' visual effects supervisor Kristijan Mrsic to remove it.