Lars Larsen was your first boss at the medical center. You had problems from the outset, because of a clash of personalities.

Then things got worse, and you filed a sexual-harassment complaint. The complaint was not sustained because of lack of specific facts presented by you (no contemporaneous notes), nor was there any corroboration. You were moved from your position to an equal one in another department.
Even though you were earnestly trying to get to know the intricacies of your new job, the manager gave you an inordinate amount of work, with short turn-around times. You subsequently got a poor evaluation, the first you had ever received. Following that poor evaluation, carefully documented, you discovered that your manager was a good friend of Lars.
Over the years, you have been able to put the poor evaluation behind you, and have been promoted up. In fact, you just received a promotion to a position for which you and Lars Larsen both competed. In your new position, you will supervise both Lars and his friend, the manager who gave you the poor evaluation.
Lars comes into your office and states that he does not believe you should be the one to evaluate his performance, because of your personality conflicts of the past, your obvious dislike for him as manifested by the sexual harassment complaint, and your statements made to co-workers some years previous concerning the poor evaluation you received at the instigation—you were then sure—of Lars Larsen.
How would approach the many components of these problems?

Handling the various components of these problems requires a thoughtful and strategic approach. Here's how you could approach each aspect:

1. Personality conflicts with Lars Larsen: Recognize that personal conflicts can impact professional relationships. However, as a professional, it is essential to separate personal feelings from your job responsibilities. Explain to Lars that although you acknowledge past conflicts, your priority is to maintain professionalism and fairness in evaluating his performance. Emphasize your commitment to treating everyone on the team fairly.

2. Sexual harassment complaint: Reiterate the facts surrounding your complaint. Explain that the complaint was made in good faith, but was not sustained due to the lack of specific facts and corroborating evidence. Stress that it is important to focus on the current situation and move forward, as dwelling on the past will not benefit either of you or the team.

3. Poor evaluation and the manager's friendship with Lars: Share that you have put the poor evaluation behind you and have moved on. Explain that as a professional, you have the ability to assess and evaluate others objectively, regardless of personal opinions or past experiences. Reinforce your commitment to providing fair and unbiased evaluations and to treating everyone on the team equally.

4. Competing for the same position: State that the promotion decision was made based on qualifications, skills, and performance, rather than personal biases. Emphasize that the promotion demonstrates recognition of your capabilities and that you will approach your new supervisory role with professionalism and fairness.

Overall, focus on maintaining open communication, expressing your commitment to professionalism and fairness, and emphasizing your ability to separate personal feelings from professional responsibilities. It is important to address and acknowledge past issues, but also to demonstrate your growth and ability to move forward in providing fair evaluations and effective leadership.