While the heros were distracted hunting diablo, [[Baal]] took advantage of this opportunity and amassed a huge army to defeat the barbarian kingdoms. With the aid of {{iw|Nihlathak Nihlathak}}, he bypassed the{{iw|Ancient|the ancients}} s and managed to corrupt the worldstone before the heros defeated him. Tyrael had to destroy it, or the tides of hell would flood into sanctuary. Known activity of hell stops here for 20 years.