Simplify the following text for a Grade 7 native English-speaking person.
Original: Ferdinando I de ' Medici , Grand Duke of Tuscany ( 30 July 1549 -- 17 February 1609 ) was Grand Duke of Tuscany from 1587 to 1609 , having succeeded his older brother Francesco I.
Simplified: Ferdinando I de ' Medici , Grand Duke of Tuscany ( 30 July 1549 -- 17 February 1609 ) was Grand Duke of Tuscany from 1587 to 1609 . He succeeded his older brother Francesco I.