Most explanations of the Gernikako Arbola, the Tree of Gernika, treat it as a pure symbol: an oak that stands for Basque self-governance, discussed the way you’d discuss a flag or a seal. What that framing leaves out is that the tree was never separated from ordinary commerce. The same 1366 document that turned the ground under the tree into a seat of law also turned the town around it into a chartered market, and that market has never stopped operating. You can watch farmers unload produce in Gernika on a Monday morning a short walk from the spot where Basque lords once swore an oath.
That distinction matters if you’re trying to understand the Basque oak tree tradition as something lived rather than something monumentalized. A symbol you only read about in a museum caption asks nothing of you. A market that has run every Monday for roughly 660 years, and a parliamentary body that still meets a few steps from the tree today, are still active institutions with hours, addresses, and a public you can walk into. Missing that turns Gernika into a static history lesson instead of a town with a functioning civic life built on medieval foundations.
This account draws on the institutional records of the Juntas Generales de Bizkaia (the General Assemblies of Bizkaia, the historical territory’s parliamentary body, which still sits in Gernika), the town’s own tourism history pages, and the Basque Government’s regional tourism authority, cross-checked against each other for dates and names. Where sources disagreed on a detail, the institutional source was treated as authoritative.
A Charter With Two Purposes
On April 28, 1366, Tello Alfonso, known as Conde Don Tello, Lord of Biscay and an illegitimate son of King Alfonso XI of Castile, issued the founding charter that created Gernika, known in Spanish as Guernica, as a villa, a chartered town, separating it administratively from the neighboring parish of Lumo. Tello was a prolific town-founder during his lordship. He also chartered Markina in 1355, Elorrio in 1356, and Gernika and Gerrikaitz together in 1366.
The charter did two things at once. It granted the new villa limited local jurisdiction, and it granted it the right to hold a weekly market. Those two grants, governance and commerce, arrived in the same document, on the same day, for the same town. Gernika’s civic and its commercial identity share a birth certificate.
The charter was significant enough that the town marked its 600th anniversary in 1966 with a monument. A statue of Conde Tello, sculpted by Agustín Herranz, stands today in Gernika’s Plaza de los Fueros, the Fueros Square, itself named for the traditional laws the town would come to symbolize.
Gernika’s location helped the charter succeed. The town sat at a junction between the coastal trade routes running through the port of Bermeo and the inland paths toward Durango, which meant the market Tello granted had merchants to draw on from the start rather than having to build demand from nothing. It is a reminder that medieval charters in this part of Spain were rarely just about who ruled; a Navarrese king once built the first fortress at Hondarribia on the Basque coast for the same reason Tello chartered Gernika, to secure a strategic point before a rival power did.
The Monday Market That Outlasted Everything Else
The market right Tello granted in 1366 is still exercised today, every Monday, in the same town. It is one of the few traditional weekly markets still operating continuously in the Basque Country, and it has run for more than 650 years without needing to be revived, relocated, or reinvented.
People from across the surrounding Busturialdea region come into Gernika on Mondays to buy and sell agricultural products. Historically the day carried a social function beyond the transactions themselves; Monday was when the district’s farms and villages actually saw each other, not just when they traded.
Twice a year the ordinary Monday market expands into something considerably larger. The First Monday of October brings a livestock fair, including the Euskadi Pirenaica cattle show, with more than 100 animals presented in various categories. The Last Monday of October is the biggest market day of the year: roughly 900 stalls, a mix of the market’s permanent vendors and visiting street sellers, fill the center of town. Judges assess entries in cheese, txakoli, honey, flowers, fruit, and vegetables early in the morning, and the prizes are awarded around midday at the town’s Mercury Fountain.
The General Assemblies of Bizkaia and the market are, in a literal sense, sibling institutions. One is a legislative body that stopped meeting for 102 years and came back. The other is a commercial tradition that never stopped at all.
The Tree That Kept Rebuilding Itself
The oak itself is not a single ancient organism. It is a lineage, and its own history undercuts the idea of an unbroken, untouched symbol standing since the Middle Ages.
The “Father Tree,” presumed planted in the 14th century, is the earliest tree in the recorded line. The tree known as the “Old Tree” grew from 1742 to 1892; its trunk is preserved nearby to this day. A successor tree stood from around 1858 or 1860 until 2004, when a fungal infection forced its replacement. The following tree, planted in 2005, died of a humidity-related disease in January 2015. The current tree has stood since 2015.
Basque government gardeners keep spare saplings on hand, each grown from an acorn of the previous tree, so that every new Tree of Gernika descends directly from its predecessor rather than being an unrelated replacement. The symbolism survives generational turnover in the actual wood, which is a more literal kind of continuity than most civic symbols get.
Where Kings Swore an Oath They Didn’t Write
Documented meetings under an oak at Gernika go back to at least the 14th century. Representatives from the parishes of Biscay gathered there to draft and uphold a body of law based on citizen representation, meetings that developed into the General Assemblies of Biscay, known in Basque as the Batzar Nagusiak.
Under that tree, the Lords of Biscay, a title held at various points by Castilian monarchs, swore to respect Biscay’s traditional laws, the fueros, before their lordship was recognized. The lord swore to a law he had not written and could not unilaterally change. That is the specific mechanism the tree symbolizes: not vague liberty, but a concrete, repeated ritual of a ruler binding himself to existing local law.
Biscay was not the only part of the old Basque and Navarrese world to govern itself this way. Navarra’s own Valle de Baztán has answered to its own written law since the 1600s, a separate tradition but the same underlying idea, local law that outranked distant kings on local matters.
The fueros were abolished in 1876, and the General Assemblies stopped meeting. They were reinstated on April 28, 1979, the same calendar date, 613 years later, as Tello’s original 1366 charter, after 102 years of suspension. Today the Juntas Generales de Bizkaia sit as the historical territory’s representative parliamentary body, and the Casa de Juntas in Gernika remains one of their traditional seats.
Earlier structures had stood beside the tree before 1826, when construction began on the Assembly House that occupies the site today. Its most striking feature is a stained-glass ceiling installed in 1985 by the Bilbao firm Vidrieras de Arte, the largest commission the company had undertaken to that point. The glasswork depicts the tree as the meeting point of Biscay’s towns, with an inscription reading “Lege Zaharra,” Basque for “Old Law,” positioned beside the Oath Stand where lords once swore their allegiance to it.
The Song, and What to Know Before You Go
The tree acquired its wider fame partly through music. The Basque bertsolari José María Iparraguirre composed and first performed “Gernikako Arbola” in Madrid on August 7, 1853, in bertso form, the traditional Basque style of improvised sung verse, honoring the tree and Biscay’s traditional liberties. Iparraguirre carried the song across the Basque Country and into the Basque diaspora in the Americas as he traveled, and it became, in practice, the unofficial anthem of Basque identity. Today only its first stanza is customarily sung as such.
For visitors, the Casa de Juntas and the tree are open to the public on a fixed schedule: mornings from 10:00 to 14:00 year-round, afternoons from 16:00 to 19:00 in summer and 16:00 to 18:00 in winter, every day except when a plenary session is in progress. The building sits at Allende Salazar Z/G in Gernika. The Monday market needs no ticket or appointment; it simply happens, the way it has happened on most Mondays since 1366.
Frequently Asked Questions
What is the Gernikako Arbola?
The Gernikako Arbola, the Tree of Gernika, is an oak in the Bizkaia town of Gernika under which representatives of Biscay’s parishes met for centuries to draft and uphold local law. Lords of Biscay swore to respect those laws, known as the fueros, beneath it before their rule was recognized. The current tree, planted in 2015, is the latest in a documented line descending from earlier trees on the same spot.
Is Gernika part of Navarra?
No. Gernika is in Bizkaia (Biscay), one of the three historical territories that make up the Basque Autonomous Community, roughly 100 kilometers northwest of Pamplona. It is a separate province from Navarra, with its own charter history, its own parliamentary body, and its own capital-territory relationship to Bilbao rather than to Pamplona. Basque identity connects the two regions more than politics does; a quarter of Pamplona itself still speaks Euskara despite sitting well outside Bizkaia.
What day is the Gernika market?
Every Monday, under the market right granted by Gernika’s 1366 founding charter. Vendors and buyers from the surrounding Busturialdea region take part. The market expands into a much larger event twice a year, on the First Monday of October (a livestock fair) and the Last Monday of October (roughly 900 stalls, the largest market day of the year).
Can tourists visit the Tree of Gernika?
Yes. The tree and the adjoining Casa de Juntas, the Assembly House, are open to the public daily except during plenary sessions, with morning hours of 10:00 to 14:00 and afternoon hours that shift seasonally. The site includes the Assembly Chamber and the 1985 stained-glass ceiling depicting the tree’s symbolism. No advance ticket is required for general visits.
Every article on the Encierro blog is authored or reviewed by active bull runners with direct experience in Pamplona.