Vincentio is the protagonist of Measure for Measure. He is the Duke of Vienna, although he appoints Angelo to rule the city in his place so that he can pose as a friar named Lodowick and secretly observe the common folk.

Vincentio possesses a great deal of power and he is considered virtuous and introspective by those who know him well. When he departs from Vienna, his plan to leave in secret denotes his humility. Rather than depart publicly, Vincentio states:

I’ll privily away. I love the people,

But do not like to stage me to their eyes:

Through it do well, I do not relish well

Their loud applause and Aves vehement (I.1.77-80).

Throughout the play, Vincentio prefers to act in secret, advising Isabella and Mariana how to act from behind the scenes and only taking a public role in dispensing justice in the very last scene. Vincentio solves problems in Vienna through craft rather than through force. While he could easily reveal his identity and force Angelo to spare Claudio, he instead devices a trick so that he can test both Angelo’s honesty and Isabella’s capacity for mercy.

Vincentio is considered to be a morally upstanding ruler by his advisor Escalus, although Lucio repeatedly claims that the duke was prone to vice.