Viola has been in a shipwreck and cast up on the coast of Illyria with the captain
Viola fears her twin brother Sebastian is drowned but Captain gives her hope that he survived
The captain tells Viola of Orsino's requited love for Olivia and Olivia's grief over her dead brother
Viola has heard her father mention Orsino previously so she decides to disguise herself as a eunuch and serve Orsino
Viola is resourceful after she has been shipwrecked and thinks about her situation, rather than succumbing to her grief or despair. This contrast her with Olivia
Viola may have adopted male clothing as some kind of physical, social and psychological protection
After scene 2, Viola isn't seen in female attire again
Eunuchs are castrated males, often having powerful positions in the Ottoman court (turkish empire)