Who, or how did Yom Kippur start?

Answer 1

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Answer 2

it was insituted in biblical times as the day on which the high priest would help the atnoment process by the completion of a series of rituals and sacrifices. the earliest computation of its date is to the coming down from mt. sinai by moses with the second set of tablets after he smashed the first set -- in the year 1313 before the common era.