This enormous palace is one of Florence's largest architectural monuments. The original palazzo was built for the Pitti family in 1457, designed by Filippo Brunelleschi and built by his pupil Luca Fancelli. The original construction consisted of only the middle cube of the present building. In 1549, the property was sold to the Medicis and became the primary residence of the grand ducal family. The palace was then enlarged and altered; from 1560, Bartolomeo Ammannati designed and added the grandiose courtyard and two lateral wings.
Today, the Pitti Palace houses some of the most important museums in Florence: on the first floor is the Palatine Gallery, containing a broad collection 16th and 17th century paintings (including works by Raphael), and the Royal Apartments, containing furnishings from a remodeling done in the 19th century.
On the ground floor and mezzanine is the Treasury of the Grand Dukes (formerly known as the the Silver Museum or Museo degli Argenti) displaying a vast collection of Medici household treasures, from table silverware to precious stone vases, rock crystals and precious jewelry.
The Gallery of Modern Art is on the top floor, holding a collection of mostly Tuscan 19th and 20th century paintings. https://www.visitflorence.com/florence-museums/pitti-palace.html