Tartuffe
National Theatre production at the Old Vic Theatre, 1967 
Role: Valère

Tartuffe (or, The Imposter) is a comedy by the French playwright Molière. It was first performed in 1664. Tyrone Guthrie directed the National Theatre production in 1967-68.

Here is a synopsis of the play:

In Paris, a rich man named Orgon lives with his two grown children, Mariane and Damis, and his young second wife, Elmire. He meets Tartuffe, who Orgon thinks is is a man of great religious zeal and piety. But in fact, Tartuffe is a hypocrite and a con man.

Tartuffe manages to convince Orgon that his family is very sinful. Orgon invites Tartuffe to live in his house to spy on Elmire to see if she is faithful. Tartuffe proceeds to try and seduce her.

Orgon also plans to break Mariane's engagement to her fiancé, Valère and promises her in marriage to Tartuffe. Mariane tells her maid, Dorine, that she would rather die than marry a manipulative person like Tartuffe, but she cannot disobey her father. She tries to convince Valère that she does not love him. However, Dorine quickly gets the two young lovers back together. 

Orgon, however, insists that the marriage of Mariane and Tartuffe take place. By the time Tartuffe is exposed and Orgon renounces him, Tartuffe has legal control of his finances and family. At the very last minute, the king intervenes, and Tartuffe is condemned to prison.

Wikipedia page about the play // Full text