The guest of honor is the oldest lady present, or a stranger whom you wish for some reason to honor.
A bride at her first dinner in your house, after her return from her honeymoon, takes, if you choose to have her, precedence over older people.
Or if a younger woman has been long away she, in this instance of welcoming her home, takes precedence over her elders.
The guest of honor is always led in to dinner by the host and placed on his right, the second in importance sits on his left and is taken in to dinner by the gentleman on whose right she sits.
The hostess is always the last to go into the dining-room at a formal dinner.