The empress may be the empress of all life, but once the life exists, it is up to the emperor to control it. While the empress is a more benevolent figure and is usually seen positively no matter what the context, feelings are pretty mixed on what the emperor should mean. It should also be noted that the emperor is purely secular. While the high priestess can have relevance to religious choices and certain conclusions can be drawn about the place of the empress, for the most part, both of these figures represent religious idols, while the emperor is a completely secular construct, representing all earthly power and nothing more.
While many people associate the empress with motherhood the emperor, being the opposite, is usually associated with fatherhood. This also pairs him with an association related to control. He is a controlling character and one that tries to assert dominance all the time. When this card appears in a spread it is usually an indication that something should or should not be controlled by the person who is being read. Knowing the course of their life and the successes and failures up to this point it should not be hard for them to find out for themselves what should and should not benefit from a bit more control.
If the emperor were to show up in the relationship slot for a standard four point spread, this would mean that you are being too controlling in the relationship if you are a man. If this is working for you, and the person that you are in a relationship with is more comfortable accepting a more submissive role, then you have played your part perfectly. Take this as merely a statement of fact. However, if you have had strife in your relationship recently, it may be because you are being too overbearing with your will. Alternatively, sometimes if you are a woman, the tarot will read your thoughts and show you that your partner is being too dominant. This can apply to either you or your partner, so it is up to you to decide which the most likely case is.
If you happened to draw the emperor card and place it on the areas in the spread that deal with finances or career, then this may be a sign that you have been working yourself into frenzy by being too controlling at the office. At times this can be the perfect place to do this, but make sure it does not interfere with productiveness for any of the staff. This can also mean that you are being too controlling with the family funding or too strict with the spending habits of yourself or others in general. Lighten up a bit and have a bit of fun with some of your money. Finally, if it shows up in the health area of your tarot spread, this probably means that you are too domineering over your own health. Do not treat your body too harshly or be afraid to take a bit of medication when you're ill.