A running of the bulls (Spanish: encierro, from the verb encerrar, 'to corral, to enclose'; Occitan: abrivado, literally 'haste, momentum'; Catalan: correbous, 'run-bulls') is an event that involves running in front of a small group of bulls, typically six but sometimes ten or more, that have been let loose on sectioned-off streets in a town, usually as part of a summertime festival. Particular breeds of cattle may be favored, such as the toro bravo in Spain, also often used in post-run bullfighting, and Camargue cattle in Occitan France, which are not fought. Bulls (non-castrated male cattle) are typically used in such events.

The most famous bull-run is the encierro held in Pamplona during the nine-day festival of Sanfermines in honor of Saint Fermin. It has become a major global tourism event, today very different from the traditional, local 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, and in the Occitan (Camargue) region of southern France. Bull-running was formerly also practiced in rural England, most famously at Stamford until 1837.
What is the most famous 'Running of the Bulls' event?
The most famous 'Running of the Bulls' event is held annually in Pamplona Spain during the nine-day festival of Sanfermines in honor of Saint Fermin.