In some ancient societies, if the King died, that meant his wife was buried with him, ready or not. I think some Viking cultures did this. Not sure about Siberia.
An old Indo-European custom. In India it was called suttee, where the wife was expected to ascend the funeral pyre with the husband. The Vikings for a time usually got a slave to accompany the dead chieftain into the afterlife. In Homer, they sacrificed Trojan captives at Patroclus' funeral games.
Ah, the good old days. /s