Juraj Jakubisko is preparing a film from the time of Great Moravian Empire, which dominated Central Europe in the 9th and 10th centuries.
The Slovak director said he might release 200 Years Of Solitude (working title) in two or three parts.
Jakubisko describes the project as an epic look at the time when the Slavic people were abandoning their pagan roots and taking up Christianity.
The director announced the project in Uherske Hradiste, Czech Republic, where his film Bathory opened the Summer Film School festival.
Jakubisko said he was pleasantly surprised by the success of Bathory.
The historical thriller has earned more than $2.4m (CZK 36m) on 300,000 admissions in its first three weeks, topping Indiana Jones And The Kingdom Of The Crystal Skull to become the top-earning film at Czech cinemas this year.