Duke Orsino is a character from William Shakespeare's play, Twelfth Night. He is the Duke of Illyria and is portrayed as a romantic figure who is infatuated with Olivia, a wealthy countess. Orsino is characterized by his melancholic nature and his obsession with love, often expressing his feelings through poetic language. Throughout the play, Orsino's pursuit of Olivia drives much of the plot. He is depicted as somewhat self-indulgent and oblivious to the feelings of others, particularly Viola, who is disguised as a man named Cesario and becomes a messenger between him and Olivia. Orsino's character explores themes of love, desire, and the complexities of human relationships.