'Royal house' in the Bible

Also Vashti the queen hath made a banquet for women, in the royal house that the king Ahasuerus hath.

And Esther is taken unto the king Ahasuerus, unto his royal house, in the tenth month -- it is the month of Tebeth -- in the seventh year of his reign,

And it cometh to pass on the third day, that Esther putteth on royalty, and standeth in the inner-court of the house of the king over-against the house of the king, and the king is sitting on his royal throne, in the royal-house, over-against the opening of the house,