The festival of San Fermín' (or Sanfermines, Basque: Sanferminak) in the city of Pamplona (Navarre, Spain), is a deeply rooted celebration held annually from 12:00, 6 July, when the opening of the fiesta is marked by setting off the pyrotechnic chupinazo,^[1] to midnight 14 July, with the singing of the Pobre de Mí. While its most famous event is the encierro, or the running of the bulls, which happens at 8:00 am from July 7th to July 14th, the week long celebration involves many other traditional and folkloric events. It is known locally as Sanfermines and is held in honor of Saint Fermin, the co-patron of Navarre. Its events were central to the plot of The Sun Also Rises, by Ernest Hemingway, which brought it to the general attention of English-speaking people. It has become probably the most internationally renowned fiesta in Spain. Over 1,000,000 people come to watch this festival.

Fermin is said to have been the son of a Roman of senatorial rank in Pamplona in the 3rd century, who was converted to Christianity by Saint Honestus, a disciple of Saint Saturninus. According to tradition, he was baptised by Saturninus (in Navarre also known as Saint Cernin) at the spot now known as the "Small Well of Saint Cernin" ^[2][3] Fermin was ordained a priest in Toulouse and returned to Pamplona as its first bishop. On a later preaching voyage, Fermin was beheaded in Amiens, France; and is now considered a martyr in the Catholic Church.^[3] It is believed he died on September 25, AD 303. There is no written record of veneration in Pamplona of the Saint until the 12th century. Saint Fermin, as well as Saint Francis Xavier, are now the two patrons of Navarre.^[3] At Pamplona, Saint Fermin; is now sometimes said to have met his end by being dragged through the streets of Pamplona by bulls, a fate more commonly attributed to his mentor, Saturnin.