In Catholicism, what can the Saints be patrons of? St. Patrick is known for evangelizing Ireland. Since most saints I hear of are also characterized as "the Patron Saint of X", I wondered what Patrick was the Patron of. According to the wikipedia article, he is a Patron Saint of Ireland along with two others.

I was expecting a position or social class. Like carpenters, miners, loggers, etc. So now I have this question. What things can a saint be a patron of?

So it seems there are patron saints for trade positions and nations.

Are there Patron Saints to:


Emotional types of people - e.g. hot-tempered, passive, patient, generous etc.
Benignly physically characterized people - e.g. blonde, green-eyed, tall, etc.
Morbidly physically characterized people - e.g. hospitalized, murdered, disfigured, etc.
Human journeys - Suffering, oppression, conquering, etc.
Types of status - e.g. wealthy, poor, leader, surf, etc.
Types of relationships - e.g. sisters, brothers, fathers, etc.
Animals or kinds of animals.
Inanimate things - e.g. candles, cake, ice cream, etc.
Earthly things - e.g. dirt, rocks, wind, rain, sunshine, the moon, stars, etc.
Characterized things - e.g. made of specific materials, lost, stolen, etc.
Holy things - e.g. relics, priestly possessions, etc.
Events - e.g. birthdays, death days, graduations, etc.
Holidays - e.g. Christmas, Easter, Lent, etc.
Others I haven't thought of.


I did find this page, which helps a bit. I see places, occupations, illnesses and their caregivers, activities (e.g. baptism) and animals. Is there some sort of logical categories that saints can be patrons of and categories that they cannot be patrons of?
A search of the Catechism, as well as of the Vatican website and of the Catholic Encyclopedia article, do not reveal any particular official protocol to decide whether a given saint is to be considered a patron saint, and of what.

Searching through the Vatican's website for the term "patron saint" yields a number of references to patron saints, including at least one document officially establishing a saint (Thomas More) as patron saint of a profession or class (statesmen). This document is a motu proprio, issued by the Pope on his own initiative, though in this case at least he was impelled by requests from others:


  Recently, several Heads of State and of Government, numerous political figures, and some Episcopal Conferences and individual Bishops have asked me to proclaim Saint Thomas More the Patron of Statesmen and Politicians. Those supporting this petition include people from different political, cultural and religious allegiances, and this is a sign of the deep and widespread interest in the thought and activity of this outstanding Statesman. 


(E Sancti Thomae Mori section 1)

It appears then that no particular protocol is required beyond the interest of the faithful and the decision of the Pope, or (in cases of older saints especially) simply a tradition of associating saints with particular causes.

As one reads through lists of patron saints, one does notice certain patterns occur. Saints are often declared patrons of:


locations (real or virtual): e.g. St. Mark as the patron of Venice, Italy; or Our Lady of Guadalupe as the patron saint of the United States; or Isidore of Seville as the patron saint of the Internet
occupations or professions: St. Thomas More, patron saint of politicians; the Blessed Virgin as patron saint of sailors (from her title "Stella Maris": "Star of the Sea")
groups of people in general: St. Stanislaus Kostka as patron saint of the young; Our Lady of Loreto (and Saint Padre Pio), patron saint of air travelers
people with specific illnesses or disabilities: St. Dymphna as patron saint of those with epilepsy; St. Damien of Molokai as patron saint of those with leprosy


Continuing through your list: the only "patron saint of relationships" I could find are Saints Joachim and Ann, parents of the Blessed Virgin and patron saints of parents. Saint Francis of Assisi is patron saint, not of animals but of ecology and ecologists. (St. Felix of Nola is apparently the patron saint of lost pets. Keep that in mind.)

Similarly, Saint Christopher is still the patron saint of travelers, though the Church admits he probably didn't exist (!!).

In terms of holidays&mdash;or holy days&mdash;those are specifically dedicated to God, or to one or more saints; but the respective saints are not called "patron saints" of those days.

Generally speaking, though, it appears that there are no particular restrictions on what saints may or may not be patrons of, nor any authoritative teaching on the subject.