The Skull Harvest is a tournament that takes place upon the world of New Badab. It is presided over by the master of the Red Corsairs, Huron Blackheart, who rules the planet. Many alien mercenaries and Chaos warbands gather, and the warbands' leaders (or the leaders' champions) fight to the death, till only the best three remain. These warriors fight in a free-for-all arena, till one triumphs. The failed leaders' skulls are presented to Blackheart, and adorn the spikes before his throne. The victor becomes the leader of all the collective warbands, as well as receiving recognition from Blackheart and a temporary honour fleet.
In or around 999.M41, the Iron Warriors Warsmith Honsou won the tournament in a bid to create an army large enough to exact his vengeance upon the Ultramarines Captain Uriel Ventris. Thanks to his victory, his army swelled from a handful of Astartes to 17,000 warriors, as well as several powerful warships from the Red Corsairs' fleet.