Complex sentence: When Judith was five she became the object of her father's political plans, her father signed the Vienna peace treatie with Premysl Otakar II of Bohemia, they decided that Judith should marry Wenceslaus, son and heir of Premysl Otakar.
Split into simpler sentences: When Judith was five, she became the object of her father's political plans. Her father signed the Vienna peace treatie with Premysl Otakar II of Bohemia, they decided that Judith should marry Wenceslaus, son and heir of Premysl Otakar.