A country estate near Cremona. Cassandro, a misogynistic nobleman, oppresses his love-hungry brother Polidoro and forbids his sister Giacinta to marry. The Hungarian captain Fracasso, who has taken up residence with them, so far unsuccessfully courts her hand in marriage. Rosina, his pretty and clever sister, is chosen to ensnare the two brothers so that Fracasso and Giacinta can reach their goal. She is supposed to wrap the brothers around her finger with feigned simplicity ("finta semplice"), play them off against each other and thus make the union possible - at least that is the plan of the housemaid Ninetta, who has her sights set on the stubborn soldier Simone.
The premiere, which was planned for Vienna, was thwarted by many; the work was probably first performed on stage in Wolfgang Amadeus Mozart's native city at the beginning of May 1769.