Throughout the ages, Catholic clergy have been styled by various titles. The most common title is Reverendus. In addition to the superlative degree thereof (Reverendissimus), clerical dignitaries also were styled with various secular titles such as Dominus (Lordship), Illustrissimus, and Amplitudinis (Grandeur). Into the twentieth century, bishops continued to be addressed as Most Reverend and Illustrious Lordship, while, in the English speaking world, archbishops were addressed, in the style of dukes, Your Grace. Cardinals were and are styled Eminence after the highest officials of the Byzantine court, and the Pope is called Sanctitas (Holiness) or Beatissimus Pater (Most Blessed or Holy Father).
The title of Excellency is secular in origin and began to be given to civil officials such as ambassadors in the eighteenth century. Thus apostolic nuncios (papal ambassadors) and other dignitaries of the papal court acquired the title Excellentia with the addition of Reverendissima to distinguish it from secular excellencies. Diocesan bishops began to acquire the title with greater frequency in the nineteenth century. For example, Metropolitan Sheptytsky, who held various state offices in the Austrian Imperial system, was addressed as Excellency inside Austria but as Illustrissimus ac Reverendissimus Dominus by the Roman Curia or Amplitudo Vestra/Votre Grandeur by other clergy.
