The great structure was designed by the Maltese architect Gerolamo Cassar (1520c.1586).He was in his 50's, it has been speculated,travelled abroad. He was able to take responsibility for much of the earlier buildingwork which characterises Valletta. Cassar was not only a trained military engineer, but he had also sevioured the latest roman trends of palatial architecture. This made him eminently suitable to take on the task of planning and designing the principle auberges and palazzi.