The professed sergeants-at-arms assisted the knights; they were at first quite important and numerous but eventually almost completely faded out of the picture, being replaced by hired help. In fact, the knights employed a considerable number of men for all their enterprises, both charitable and military: physicians and other personnel in the hospital were engaged on a paid basis, the soldiers who formed the body of the order’s army were mercenary troops as were the sailors on their fleet in the days of Rhodes and Malta. At the top of this hierarchical pyramid stood the Master. His official title, ever since the days of Blessed Gerard, was Master of the Hospital. Although often referred to, even in earlier days, as the Grand Master, he did not formally assume the latter title until 1489. After the order had settled on Malta, the Grand Master Alof de Wignacourt (1601-1622) was given the title of prince of the Holy Roman Empire by the Emperor and the Pope bestowed on him and his successors a rank equal to a Cardinal of the Holy Roman Church with the title of Eminence. Besides these sonorous titles, the grand master, like all other professed members of the order, also uses the religious title Frà (Brother) which is put before his baptismal name. To date there have been seventy-six grand masters. The monastic habit of the order was a wide black cassock with a slit on each side for the arms. In the days of Blessed Gerard a plain white cross was sewn on the breast; Master Raymond introduced the eight-pointed white cross which has become the emblem of the order down to the present day. Since these bell-like cloaks were rather cumbersome in battle, Pope Innocent IV in 1248 granted the knights permission to wear a black surcoat over armour when on active service. Pope Alexander IV in 1259 changed the color of this tunic to red, with a plain white cross. The choir dress of the professed knights is even at present a black mantle with the Maltese cross and a very elaborate maniple. The headquarters of the order, wherever they might be, in Jerusalem, Acre, Rhodes or Malta, were called the Convent. In its developed form this Convent consisted of the palace of the grand master, the living quarters of the knights and their assistants, the stables for the horses, the church and the hospital.