Former Bosnian Serb leader Radovan Karadzic will appear in court again Monday when he contests his conviction for genocide and a 40-year prison sentence before U.N. appeals judges.

Karadzic was convicted in 2016 for some of the worst war crimes committed as the former Yugoslavia broke apart, including the 1995 Srebrenica massacre.

Now 72, Karadzic was found guilty on 10 counts of genocide, war crimes and crimes against humanity for the brutal campaign of ethnic cleansing in Bosnia he oversaw as president of the breakaway Bosnian Serb Republic.