A running of the bulls (Spanish: encierro, from the verb encerrar, 'to corral, to enclose'; Occitan: abrivado, literally 'haste, momentum'; Catalan: bous al carrer 'bulls in the street', or correbous 'bull-runner') is an event that involves running in front of a small group of bulls, typically six[1] but sometimes ten or more, that have been let loose on sectioned-off streets in a town,[1] usually as part of a summertime festival.

More traditional summer bull-runs are held in other places such as towns and villages across Spain and Portugal, in some cities in Mexico,[3] and in the Occitan (Camargue) region of southern France.

The event has its origins in the old practice of transporting bulls from the fields outside the city, where they were bred, to the bullring, where they would be fought and killed in the evening.

After years of this practice, the transportation and hurrying began to turn into a competition, as young adults would attempt to race in front of the bulls and make it safely to their pens without being overtaken.

[6][7] The Pamplona[2] encierro is the most popular in Spain and has been broadcast live by Televisión Española, the public Spanish national television service, for over 30 years.

[9] Most runners dress in the traditional clothing of the festival which consists of a white shirt and trousers with a red waistband (faja) and neckerchief (pañuelo).

[2] The fastest part of the route is up Santo Domingo and across the Town Hall Square, but the bulls often became separated at the entrance to Estafeta Street as they slow down.

[14] Another major risk is runners falling and piling up (a "montón", meaning "heap") at the entrance of the bullring, which acts as a funnel as it is much narrower than the previous street, resulting in a crowd crush.

The encierro of Pamplona has been depicted many times in literature, television or advertising, but became known worldwide partly because of the descriptions of Ernest Hemingway in books The Sun Also Rises and Death in the Afternoon.

Filmmakers traveled to Spain to shoot the actual running of the bulls with second unit director, Heston Fraser.

City Slickers director, Ron Underwood, recreated the Pamplona location on the Universal Studios backlot to stage the running of the bulls with the actors.

The run appears in the 2011 Bollywood movie Zindagi Na Milegi Dobara, directed by Zoya Akhtar, as the final dare in the bucket list of the three bachelors who have to overcome their ultimate fear; death.

Running with Bulls, a 2012 documentary of the festival filmed by Construct Creatives and presented by Jason Farrel, depicts the pros and cons of the controversial tradition.

[25] From 2014 until 2016, the Esquire Network broadcast the running of the bulls live in the United States,[26] with both live commentary and then a recorded 'round up' later in the day by NBCSN commentators the Men in Blazers, including interviews with noted participants such as Madrid-born runner David Ubeda,[27] former US Army soldier turned filmmaker Dennis Clancey,[28] and former British bullfighter and author Alexander Fiske-Harrison.

[29] In 2014, a guidebook authored by Alexander Fiske-Harrison, Ernest Hemingway's grandson John, Orson Welles' daughter Beatrice, and with a foreword by the Mayor of Pamplona, caused headlines around the world when one of the contributors, Bill Hillmann, was gored by a bull soon after its publication.

[30] The award-winning 2015 feature documentary Chasing Red directed by Dennis Clancey, follows four runners during the 2012 fiesta in Pamplona, including Bill Hillmann and David Ubeda.

[31][32][33] Although the most famous running of the bulls is that of San Fermín,[2] they are held in towns and villages across Spain, Portugal, and in some cities in southern France during the summer.

Examples are the bull run of San Sebastián de los Reyes, near Madrid, at the end of August, which is the most popular of Spain after Pamplona; the bull run of Cuéllar, considered as the oldest of Spain since there are documents of its existence dating back to 1215; the Sanjuanes of Coria (Cáceres, Extremadura) since XV century is original and dangerous; the Highland Capeias of the Raia in Sabugal, Portugal, with horses leading the herd crossing old border passes out of Spain and using the medieval 'Forcåo'; and the bull run of Navalcarnero held at night.

[34] Bous al carrer, correbou or correbous (meaning in Catalan, 'bulls in the street', 'street-bulls' or 'bull-running') is a typical festivity in many villages in the Valencian region, Terres de l'Ebre, Catalonia, and Fornalutx, Mallorca.

[35] Numerous bull-running events happen in France in the region around Sommières, in accordance with the Camargues tradition, in which no bulls are intentionally injured or killed.

[37] According to local tradition, the custom dated from the time of King John when William de Warenne, 5th Earl of Surrey, saw two bulls fighting in the meadow beneath.

The earl mounted his horse and rode after the animal, and enjoyed the sport so much that he gave the meadow in which the fight began to the butchers of Stamford, on condition that they should provide a bull to be run in the town every 13 November, for ever after.

In modern times, the bull is often replaced by a runner carrying a frame on which fireworks are placed, and dodgers, usually children, run to avoid the sparks.

[39] The Big Easy Rollergirls roller derby team has performed an annual mock bull run in New Orleans, Louisiana since 2007.

[46] The city of San Miguel de Allende, Mexico, cancelled its Sanmiguelada running of the bulls after 2006, citing public disorder associated with the event.