Janosik is a Slavik folk hero, fighting the bad landowners who oppress the good peasants. Based on a real highway robber who was hanged in 1713, when he was twenty-five, in what became Slovakia, the legend grew into Robin Hood proportions.
Better, even--an online version reports that "he married the Queen of Elfs after 7 years of his death," which even Robin Hood couldn't do.
But then, Robin Hood didn't have these nifty braids. Really, though, Janosik wasn't dead because, "You cannot kill Janosik. Janosik is freedom and freedom is endless!"
There are zillions of stories, songs, etc. about him, including the 1935 film this poster advertises.
If you're interested in Slovak film, the online journal KinoKultur devotes an entire issue to it:
Special Issue 3: Slovak Cinema (December 2005).