'Rule' in the Bible

So the work of the house of God at Jerusalem came to an end; so it was stopped, till the second year of the rule of Darius, king of Persia.

And the building of this house was complete on the third day of the month Adar, in the sixth year of the rule of Darius the king.

And he came to Jerusalem in the fifth month, in the seventh year of the king's rule.