When The Emperor appears in a spread it often refers to a person in a position of authority; they have a good sense of their own importance. This person could be a man or a woman.
If this card is referring to you instead of someone else, it is reminding you of your own power and influence; it could be trying to tell you that you have more power and ability than you give yourself credit for. You must believe in yourself before you can expect anyone else to.
Or you may need to take control of a difficult situation rather than allow things to drag on. You may even need to show the steely part of your nature; show them that although you prefer to resolve things in a peaceful manner you are prepared for battle if necessary.
The Emperor is a man whose head rules his heart; so this card may be telling you to make some hard decisions, decisions that you might not want to make but that are crucial.
If the card appears upside down, it may be indicating a loss of control, serious injury in battle or emotional immaturity.