What is the historical origin of this hat [image] - worn by Pope Ratzinger Can anyone explain the origin &mdash; i.e., when it was first used, the Pope who wore it the first time and when, its name &mdash;  of that red hat worn by Pope Ratzinger?
Pope Emeritus Benedict XVI (formerly known as Joseph Cardinal Ratzinger) is depicted above wearing what is known as a "cappello romano," which is Italian for "Roman hat."

It does not originate from papal attire, but was simply a fashionable hat worn by 17th century clergy. 

From wikipedia:


  A cappello romano (literally Roman hat in Italian) or saturno (because
  its appearance is reminiscent of the ringed planet Saturn) is a hat
  with a wide, circular brim and a rounded crown worn outdoors in some
  countries by Catholic clergy, when dressed in a cassock. It is made of
  either beaver fur or felt, and lined in white silk. Unlike many other
  articles of ecclesiastical attire, it serves no ceremonial purpose,
  being primarily a practical item.  The cappello romano is not used in
  liturgical services. Since the general abandonment of the cassock as
  street dress, it is uncommon even in Rome today, though it was quite
  popular there and in some other countries with a Catholic majority
  population from the 17th century until around 1970.
  
  There are some, mostly minor, differences in the designs of cappelli,
  depending on the rank of the wearer. The pope wears a red cappello
  with gold cords. Cardinals formerly also had the privilege of wearing
  a red cappello, but this rule was overturned by Paul VI, and now
  Cardinals' cappelli are black, as are those of all other clerics.