The idea of fortifying the rocky and steep-sided Mount Sciberras had occured to the Knights on their arrival in 1530, but because time was not on their side, they limited themselves to building a fort at its very tip, instead.

If other Grand Masters studied the possibilities of such a project, La Valette was obsessed with the idea: as soon as he had been elected to the Grand Mastership in 1557 he invited foreign military engineers, famous in their time, to prepare the plans, but the Great Siege put a stop to all that.

No sooner was the siege lifted than the plans for the fortress city were again revived, but as a first step the ill-fated fort St. Eimo was at once rebuilt.

Pope Pius IV sent his military engineer, Francesco Laparelli, and the planning of the new town started in earnest.

When Laparelli departed from the Island he left his Maltese assistant, Gerolamo Cassar, to continue the work he had started. La Valette died in 1568 and was buried in the church of Our Lady of Victories, the first building to be erected.

Other Grand Masters continued to embellish the new city and, in time, all the important buildings of the Order were enclosed within its walls: the Auberges of the Langues of the Order; the Grand Master's Palace with its Armoury; the Co-Cathedral and other churches: the Hospital; the Courts of Justice and the palatial houses of individual Knights, rich Maltese citizens, and ecclesiastics.