Premise: After a brief stint living in the Palazzo Vecchio in the Piazza della Signoria, Duke Cosimo I and his wife, Eleonora of Toledo, acquired the palace from the bankrupt Pitti merchant family in 1549 as the Medici's official residence; it was enlarged and embellished substantially over the centuries.

Hypothesis: The Medici's official residence used to belong to the Pitti family.
Relation: entailment