'Kings' in the Bible

And ye shall be brought before governors and kings for my sake, for a testimony against them and the Gentiles.

But what went ye out for to see? A man clothed in soft raiment? behold, they that wear soft clothing are in kings' houses.

He saith, Yes. And when he was come into the house, Jesus prevented him, saying, What thinkest thou, Simon? of whom do the kings of the earth take custom or tribute? of their own children, or of strangers?