The Running of the Bulls happens every year since 1591 in Pamplona.(in Spanish encierro, from the verb encerrar,to fence in, to lock/shut up, to pen) The origin of this event comes from the need to transport the bulls from the off-site corrals where they had spent the night, to the bullring where they would be killed in the evening. Youngsters would jump among them to show off their speed, strenght, etc. Spanish tradition says the true origin of the run began in northeastern Spain during the early 14th century. While transporting cattle in order to sell them at the market, men would try to speed the process by hurrying their cattle using tactics of fear and excitement Years later, the transportation changed to competence. When the popularity of this practice increased and was noticed more and more by the expanding population of Spanish cities, a tradition was created and stands to this day.
Animal rights groups protest against the tradition.
The Pamplona “encierro” is the most popular in Spain and is broadcast live by two national television channels. It is the highest profile event of the San Fermin Festival, which is held every year from July 6–14. The first bull running is on July 7, followed by one on each of the following mornings of the festival, beginning every day at 8 am. Participants must be at least 18 years old, run in the same direction as the bulls, not incite the bulls, and not be under the influence of alcohol.
A first rocket is set off at 8 a.m. to alert the runners that the corral gate is open. A second rocket signals that all six bulls have been released. The third and fourth rockets are signals that all of the herd has entered the bullring and its corral respectively, marking the end of the event. The average duration between the first rocket and the end of the encierro is four minutes.