Simplify the following text for a Grade 8 native English-speaking person.
Original: In the Middle Ages it was a possession of the Aldobrandeschi family , who held it until the 14th century , when it was acquired by the city of Orvieto .
Simplified: In the Middle Ages it was controlled by the Aldobrandeschi family , who held it until the 14th century , when it was bought by the city of Orvieto .