Ascendancy is a 1983 British film. It tells the story of a woman who is a member of the British landowning 'Ascendancy' in Ireland during World War I. Gradually, she learns about the Irish independence movement, and becomes involved with it.

Harry Webster (David Lyon) is an apparently normal husband and father who resides in contemporary Nottingham, England, which was once host to a flourishing textile industry. One day, Harry leaves his house and vanishes. A note he left behind alludes to a double life he no longer wishes to lead. His wife Liz (Annette Crosbie) conducts a search for her husband. Her findings raise a disturbing question: Did Harry have anything to do with a series of recent factory bombings?

In this story-within-a-story, Anna is an actress starring opposite Mike in a period piece about the forbidden love between their respective characters, Sarah and Charles. Both actors are involved in serious relationships, but the passionate nature of the script leads to an off-camera love affair as well. While attempting to maintain their composure and professionalism, Anna and Mike struggle to come to terms with their infidelity.