Most guides describe Aste Nagusia, Bilbao’s nine day “Big Week,” as if it were an old Basque custom that simply grew larger over the decades. It wasn’t. The participatory festival visitors experience today, with its neighborhood clubs, street bars and giant papier mâché mascot, was designed on a deadline by ordinary residents who entered a public idea contest in the spring of 1978, after decades of a stiff, paid festival program that most bilbaínos never took part in.
That distinction matters for anyone planning around it. A traveler who assumes Aste Nagusia is an ancient tradition misses the actual reason it feels so different from a typical municipal festival: it was built from the ground up by the people who show up to it every year, not handed down by a church calendar or a royal decree. It also gets confused, constantly, with a festival of almost the identical name held in a different Basque city on different dates. Getting the two straight is the difference between planning a trip that works and one that doesn’t.
This article draws on the Ayuntamiento de Bilbao‘s own festival records, the Basque Government’s Turismo Euskadi event listings, and the documented, sourced account of the festival’s founding maintained on its Wikipedia entry, which traces back to contemporary reporting in El Correo, Cadena SER and ElDiario.es. Every date and figure below is cross checked against at least two of those sources.
The 1978 Contest That Built It
Before 1978, what Bilbao called its “Semana Grande” was a program of paid spectacles and formal religious observances, run from the top down with little connection to the city’s own neighborhoods. That started to change in 1973, when a one-off week of free Basque rural sports demonstrations drew a genuinely large public crowd, and again in 1977, when a local radio broadcaster’s on-air call for a trial street procession pulled roughly 5,000 residents into the Casco Viejo, far more than anyone expected.
Riding that momentum, the city and a department store sponsor launched a formal public competition in the spring of 1978 titled “Hagamos populares las Fiestas de Bilbao,” inviting any resident to submit a concept for a genuinely popular festival. Proposals were accepted for two months. Thirty seven were submitted. On June 9, 1978, a jury split evenly between city officials and neighborhood association representatives selected a winning concept from a cultural collective active in Bilbao’s own associational movement.
A seventeen member organizing committee, drawn entirely from that movement with no sitting councillors on it, formed within weeks and set to work on a budget of roughly 8.4 million pesetas. It picked the Arenal and the Casco Viejo, the same streets still used today, as the festival’s home. Neighborhood groups and friend circles were invited to organize themselves into comparsas, known in Basque as konpartsak, each required to field a band, at least fifty members in matching dress, and its own street bar stall, or txosna. Organizers expected perhaps eight of these clubs to form in time. Twenty four did, representing more than 1,600 people, before the festival had even opened.
Marijaia, Built in Five Days
A festival built from scratch needed a symbol, and Bilbao’s now most recognizable one arrived almost as an afterthought. Barely a week before the first festival opened, the organizing committee commissioned painter and engraver Mari Puri Herrero to design a mascot based on the Dama de Anboto, a female figure from older Basque mythology. Herrero built the four metre tall figure, arms permanently raised as if mid dance, in five days.
That figure, Marijaia, first appeared on the afternoon of August 19, 1978, in Bilbao’s Begoña district, when txupinera María Jesús Aguirregoitia fired the opening rocket that launched the modern Aste Nagusia. The turnout exceeded even the organizing committee’s expectations, and the week closed with the ritual burning of Marijaia over the ría, a closing rite the city has repeated every year since. The first edition finished with a surplus of roughly 360,000 pesetas, which the committee reinvested in permanently rebuilding Bilbao’s own gigantes, or giant processional figures, a tradition dating to the 1500s that had lapsed by 1978. Since 1997, Marijaia has had her own anthem, “Badator Marijaia,” composed by Basque musician Kepa Junkera.
Marijaia’s staying power is not a matter of local sentiment alone. In 2009, Spain named Aste Nagusia to its list of Intangible Cultural Heritage Treasures, ranking it first in that year’s national public vote, official recognition of a festival that was, at the time, barely three decades old.
The Year the City Took It Back, and the Compromise That Followed
The festival’s popular model nearly didn’t survive its second birthday. In 1980, Bilbao’s city government moved to take direct control of festival organizing away from the neighborhood coalition that had built it. What resulted was a diminished, city run version of the week that, by contemporary accounts, had no Marijaia, no red neckerchiefs, no txupinera and no participating comparsas at all.
Public pushback over that one flat year forced a compromise the following year. In 1981, a joint commission, seated equally by elected councillors and by representatives of the comparsas’ own federation, took over governing the festival, and that power sharing structure still runs it today. The same year also brought Bilbao’s now signature nightly fireworks competition, launched at the comparsas federation’s own request.
Not Donostia’s Semana Grande
Here is where most planning goes wrong. San Sebastián, known in Basque as Donostia, holds its own festival also called Semana Grande, organized by a completely different city government, with its own separate history and its own signature international fireworks competition, one that predates Bilbao’s by 17 years. The two events are not the same festival under two names, and they do not share dates.
In 2026, Donostia’s Semana Grande runs from August 8 through August 15. Bilbao’s Aste Nagusia begins the following Saturday, August 22, and runs through August 30. The two never overlap, and there is a full week between them, enough time for a visitor working through the Basque Country after San Fermín to genuinely plan for both rather than accidentally choosing one while thinking they’ve booked the other. For the specifics on Donostia’s own version, including its 1876 origin and its judged, prize-structured fireworks competition, see Encierro’s dedicated guide to San Sebastián’s Semana Grande.
Konpartsak and Txosnas Today
The konpartsak that formed in that first summer of 1978 are still the organizational backbone of the festival, Bilbao’s rough equivalent to Pamplona’s own peñas, though built and governed on different lines. Each konpartsa still runs its txosna in the Arenal festival grounds through all nine days, serving food, drink and music, and the federation that represents them, Bilboko Konpartsak, still sits on the joint commission that governs the week alongside the city council. In 2026, the official program lists more than 100 free musical performances spread across nine different festival spaces over the nine days, a scale the 1978 organizers, expecting eight clubs and a few thousand participants, could not have anticipated.
Frequently Asked Questions
What is Aste Nagusia?
Aste Nagusia, Basque for “Big Week” and known in Spanish as Semana Grande de Bilbao, is Bilbao’s main annual festival, held over nine days beginning the first Saturday after August 15 each year. It centers on neighborhood clubs called konpartsak, their street bars, free concerts, nightly fireworks and the festival’s mascot, Marijaia.
Is Aste Nagusia the same as Semana Grande in San Sebastián?
No. Donostia/San Sebastián holds its own, separately organized Semana Grande, with a different history and its own fireworks competition dating to 1964. The two festivals share a Spanish name by coincidence of translation, not by any shared organization, and in 2026 they run back to back without overlapping, Donostia’s from August 8 to 15 and Bilbao’s from August 22 to 30.
How old is Aste Nagusia?
The participatory format familiar today dates to 1978, when a citizen idea competition redesigned what had previously been a paid, top down festival program. It is a modern civic invention, not a centuries old tradition, though it draws on older Basque elements it deliberately revived, including the gigantes processional figures and the Dama de Anboto myth behind the Marijaia mascot.
When is Aste Nagusia 2026?
Bilbao’s Aste Nagusia 2026 runs from Saturday, August 22 through Sunday, August 30.
Every article on the Encierro blog is authored or reviewed by active bull runners with direct experience in Pamplona.