Black Council
In the history of Ukraine, the Black Council was a council of Ukrainian Cossacks in which participated a large number of ordinary Cossacks, as well as local commoners. The name comes from the Ukrainian word чернь, a demeaning term for rank-and-file Cossacks and lowly folk in general, "plebs". The most famous of these was the Black Council of 1663.
Usually Black Rada signified drastic changes among the starshyna.