Duke Cosimo I de' Medici (later to become grand duke) moved his official seat from the Medici palazzo in via Larga to the Palazzo della Signoria in May 1540, signalling the security of Medici power in Florence. When Cosimo later removed to Palazzo Pitti, he officially renamed his former palace to the "Palazzo Vecchio", the "Old Palace", although the adjacent town square, the "Piazza della Signoria", still bears the original name. Cosimo commissioned Giorgio Vasari to build an above-ground walkway, the Vasari corridor, from the Palazzo Vecchio, through the Uffizi, over the Ponte Vecchio to the Palazzo Pitti. Cosimo I also moved the seat of government to the Uffizi.