This is TRUE!
That way all battles and all people who died could be commemorated equally. Additionally, it was a good time, because flowers for decoration were more available at the time.
Because they did not have the technology to resist without getting killed
When diverse African empires, small to medium-sized nations, or kinship groups came into conflict for various political and economic reasons, individuals from one African group regularly enslaved captives from another group because they viewed them as outsiders.