born in kraków on 18 january 1519, isabella was the oldest child of king sigismund i the old and his italian wife bona sforza. she spent most of her childhood at wawel castle in kraków and the hunting castle in niepołomice. she also lived in the grand duchy of lithuania in 1527–29 and 1533–36. during the latter visit her three younger sisters were left in kraków. this episode foreshadowed future family relationships: bona sforza favored her oldest daughter, arranging her marriage early, while the other three daughters were neglected and married late. isabella received a good education, including from humanist johannes honter, and she could speak and write four languages: polish, latin, german, and italian (her mother's native language).