The palace as we see it now has been in existence from the middle of the sixteenth century. Certain internal changes and rebuildings have occurred, but its facades on the Piazzetta and lagoon, the Giants' Stairs, the courtyard, were then as now. But before that time constant structural modification was in progress. The original palace ran beside the Rio del Palazzo from S. Mark's towers to the Ponte di Paglia, with a wing along the lagoon. Its width was equal to that from the present Noah or Vine Corner by the Ponte di Paglia to the fifth column from that corner. Its wing extended to the Piazzetta. A wall and moat protected it, the extent of its ramparts being practically identical with the extent of the present building. This, the first, palace was erected in the ninth century, after the seat of government was changed from Malamocco to Venice proper. [Illustration: THE PONTE OF PAGLIA AND THE BRIDGE OF SIGHS, WITH A CORNER OF THE DOGES' PALACE AND THE PRISON] Various conflagrations, in addition to the growing needs of the State, led to rebuilding and enlargement. The first wing was added in the twelfth century, when the basement and first floor of the portion from the Porta della Carta to the thick seventh column from the Adam and Eve group, under the medallion of Venice, on the Piazzetta facade, was set up, but not in the style which we now know. That was copied three centuries later from the Riva or lagoon facade. In 1301 the hall above the original portion on the Rio del Palazzo side, now called the Sala del Senato, was added and the lagoon wing was rebuilt, the lower arches, which are there to-day, being then established. A few years later, a still greater hall being needed, the present Sala del Maggior Consiglio was erected, and this was ready for use in 1423. The lagoon facade as we see it now, with its slender arches above the sturdy arches, thus dates from the beginning of the fifteenth century, and this design gave the key to the builders of later Venice, as a voyage of the Grand Canal will prove.