A ship broke apart at sea. Viola was washed onto a strange shore and barely lived. Her twin brother Sebastian had been aboard, and she could not find him, so she believed he was drowned.
This country was called Illyria. Viola knew nobody there and had nowhere to go. She decided to wear men’s clothes and live under the name Cesario. As a young man she could get a place in Duke Orsino’s household.
Orsino had loved a lady called Olivia for a long time. Olivia had sworn, after her brother died, to see nobody for seven years. Within days the duke had taken to his new servant, and he gave him an errand.