The Gentiluomo of the Archbishop of Westminster in the Roman Catholic Church of the United Kingdom was a bodyguard (compare the royal Gentleman at arms) and personal attendant to the Archbishop.
The title originates from the Latin gentilis homo (gentleman) by way of Italian, gentile uomo. When the Archbishop was created a Cardinal, his bodyguard could accordingly be called Gentiluomo of the Cardinal Archbishop of Westminster.
The Gentiluomo's job was to guard his master, as the Archbishop was not permitted to carry a weapon (in accordance with his role as a cleric).
The position of Gentiluomo was effectively hereditary.
The appointment is now, however, in desuetude, following the death of the last Gentiluomo, Anthony Bartlett OBE (an uncle to Jennifer Paterson), in 2001. No new Gentiluomo has been appointed by either of Cardinal Hume's successors as archbishop.
Keepers of the Kingdom, UK-2001