Don is derived from the Latin dominus: a master of a household, a title with background from the Roman Republic in classical antiquity.
With the abbreviated form having emerged as such in the Middle Ages, traditionally it is reserved for Catholic clergy and nobles, in addition to certain educational authorities and persons of high distinction.
The feminine equivalents are Doña (Spanish: [ˈdoɲa]), Donna (Italian: [ˈdɔnna]), Doamnă (Romanian) and Dona (Portuguese: [ˈdonɐ]) abbreviated 'D.ª', 'Da.
In present-day Hispanic America, the title Don or Doña is sometimes used in honorific form when addressing a senior citizen.
The treatment gradually came to be reserved for persons of the blood royal, e.g. Don John of Austria, and those of such acknowledged high or ancient aristocratic birth as to be noble de Juro e Herdade, that is, "by right and heredity" rather than by the king's grace.
However, there were rare exemptions to the rule, such as the mulatto Miguel Enríquez who received the distinction from Philip V due to his privateering work in the Caribbean.
For example, despite having a doctoral degree in theology, the Paraguayan dictator José Gaspar Rodríguez de Francia was usually styled as "Don".
Likewise, despite being a respected military commander with the rank of Brigade General, Argentine Ruler Juan Manuel de Rosas was formally and informally styled "Don" as a more important title.
In the Spanish colonial Philippines, this honorific was reserved to the nobility, the prehispanic datu[15] that became the principalía,[16]: 218 whose right to rule was recognised by Philip II on 11 June 1594.[17]: tit.
[19] The practise slowly faded after World War II, as heirs of the principalía often did not inherit the title, and as civic leaders were chosen by popular election.
Officially, Don was the honorific title exclusively reserved for a member of a high noble family such a principe or a duca, excluding a marchese or a conte (and any legitimate, male-line descendant thereof).
It was, over time, adopted by organized criminal societies in Southern Italy (including Naples, Sicily, and Calabria) to refer to members who held considerable sway within their hierarchies.
In modern Italy, the title is usually only given to Roman Catholic diocesan priests (never to prelates, who bear higher honorifics such as monsignore, eminenza, and so on).
Strictly speaking, only females born of a nobleman bearing the title Dom would be addressed as Dona ('D.ª'), but the style was not heritable through daughters.
In Portugal and Brazil, Dom (pronounced [ˈdõ]) is used for certain higher members hierarchs, such as superiors, of the Roman Catholic and Eastern Orthodox churches.
[1] Unless ennobling letters patent specifically authorised its use, Dom was not attributed to members of Portugal's untitled nobility: Since hereditary titles in Portugal descended according to primogeniture, the right to the style of Dom was the only apparent distinction between cadets of titled families and members of untitled noble families.
In the United States, Don has also been made popular by films depicting the Italian mafia, such as The Godfather trilogy, where the crime boss is given by his associates the same signs of respect that were traditionally granted in Italy to nobility.
This title has in turn been applied by the media to real-world mafia figures, such as the nickname "Teflon Don" for John Gotti.