The Battle on the Planta in the Zurich and Swiss Chronicle by Gerold Edlibach, between 1506 and 1566.
The Confederate troops under Bernese and Solothurn banners in brutal hand-to-hand combat against the Savoy army: The Battle on the Planta in the Zurich and Swiss Chronicle by Gerold Edlibach, between 1506 and 1566. Zentralbibliothek Zürich

The Battle on the Planta

The Valaisans and their Swiss allies defeated a powerful Savoyard army on November 13, 1475 just beyond the gates of Sion. Though little-known outside of Valais today, the Battle on the Planta was of resounding importance to Valais, Savoy, the Old Swiss Confederation, and Burgundy. Had the Valaisans and their Swiss allies lost the battle, Valais and the Confederation would have found themselves at the mercy of Savoy and Burgundy at the height of the Burgundian Wars.

James Blake Wiener

James Blake Wiener

James Blake Wiener is a world historian, Co-Founder of World History Encyclopedia, writer, and PR specialist, who has taught as a professor in Europe and North America.

Website: worldhistory.org
It is understandable that many would find it unusual that Valais played any role or held any importance during the Burgundian Wars (1474-1478) at first glance. However, nothing could be further from the truth. Valais’ importance was and remains defined by its geography. Set between a complex network of alpine peaks, rivers, and valleys, and flanked by the bluffs of the fertile Rhône River, Valais guards the Great St. Bernard Pass and the Simplon Pass. Political control over Valais ensured tremendous, strategic advantages and riches to whomever dominated the region. By the end of the Middle Ages, Valais was the locus of ever-shifting competition between various factions. The younger sons of feudal nobles from Savoy and Valais had typically filled the role of Bishop of Sion, and so conflict between the bishops and Valaisan elites was commonplace. However, from the 1420s onwards, a noticeable shift in power emerged. The Seven Zenden of Upper Valais – Goms, Brig, Visp, Raron, Leuk, Siders, and Sion – took the upper hand, gaining political rights and consolidating their executive powers over the bishops of Sion. The erosion of the old feudal privileges was so extreme that Bishop William IV of Raron even had to relinquish civil and criminal jurisdiction to the Seven Zenden through the Treaty of Naters in 1446. Successive bishops of Sion not only quarreled with the senior leaders of the Seven Zenden, but also with the duchy of Savoy over spiritual and temporal authority in Lower Valais. Sion’s bishops coveted the old, lost episcopal possessions in Conthey and all rights to St. Théodule. Moreover, Valaisan treaties with Savoy in 1384 and 1392 divided Valais and the diocese of Sion in half, which created an eternal source of animosity and mutual distrust.
The Duchy of Savoy around 1475.
The Duchy of Savoy around 1475. Wikimedia / Marco Zanoli
The Swiss Confederation around 1474.
The Swiss Confederation around 1474. Wikimedia / Marco Zanoli
Throughout the 1460s and 1470s, Bishop Walter II of Supersaxo of Sion viewed Duke Amadeus IX of Savoy and his French wife, Yolande de Valois, with deep suspicion and contempt. As Yolande was the true arbiter of power in Savoy given her husband’s eccentric religious interests and bouts of epilepsy, Walter carefully noted her every diplomatic move. Walter believed that the couple encouraged sedition among the great families of the Seven Zenden and feared that the Savoyards would move to incorporate Sion as part of their domains. Despite the Valaisan-Milanese agreements regarding alpine transportation and border security signed in 1422 and reaffirmed in 1454, Walter worried about the potential of Savoyard-Milanese collusion as well. When relations between Savoy and Milan became ever closer through the marriage of Amadeus’ sister, Bona of Savoy, to Duke Galeazzo Maria Sforza in 1468, Walter had every reason to expect Savoyard support of Milanese territorial expansion at his expense. Tensions ran high, but aside from the occasional border skirmish, a strained peace held until 1475.
The Duchess of Savoy, Yolande de Valois (left), in a dedication in the manuscript Rhetorica by Guillaume Fichet, 1471.
The Duchess of Savoy, Yolande de Valois (left), in a dedication in the manuscript Rhetorica by Guillaume Fichet, 1471. The manuscript begins with this large miniature, depicting the author dedicating his book to the Duchess. Cologny, Fondation Martin Bodmer

International Tensions Boil Over

The clash between Burgundy and the Old Swiss Confederation had as much to do with Burgundian attempts to vanquish the Confederation as it did with safeguarding Savoy from potential Swiss encroachment. Charles “the Bold,” duke of Burgundy, needed Savoy to shield Burgundian troop movements as he prepared to attack the Swiss. Savoy was of supreme logistical importance too as it controlled the routes to Milan from Burgundy, the former being where Charles hired the majority of his mercenary soldiers. Italian mercenaries recruited by Charles began to traverse Savoy in large numbers in the spring of 1473. This greatly unnerved the Swiss, who correctly surmised that these mercenaries could be used not only against them but also their allies, Basel, Strasburg, and Lorraine. Although Yolande was the beloved sister of the pro-Swiss Louis XI of France, she oscillated between the pro-French and pro-Burgundian factions at the royal courts in Chambéry and Torino. It was only when Charles offered the hand of his daughter and heir Mary of Burgundy to her son Philibert I that Yolande sided with Burgundy against France and the Confederation. She placed an economic embargo on the Confederation in 1473, in the anticipation of armed conflict, receiving an elite guard of 80 Burgundian mercenaries as a token of appreciation from Charles soon thereafter.
Charles the Bold, portrait c. 1460, a work by Rogier van der Weyden.
Charles the Bold, portrait c. 1460, a work by Rogier van der Weyden. Gemäldegalerie Berlin, © bpk-Bildagentur
Conscientious of the events unfolding around him and well-aware of the precarious position that awaited Valais if the Savoyards and the Burgundians proved successful against the Swiss, Walter chose to play for time. Walter knew that if he allied with the Swiss, he could reclaim territories lost to Savoy, while strengthening his own position vis-à-vis the Seven Zenden in turn. An energetic and shrewd man, Walter followed Swiss military preparations against Burgundy in the Jura, as well as the flurry of diplomacy between Savoy, Burgundy, and Milan over the course of a year. Indignation on the part of the Valaisans and Swiss alike erupted when news of an alliance between Milan, Savoy, and Burgundy – the so-called League of Moncalieri – reached Sion and Bern in February 1475. The moment Walter finally waited for came to pass in September 1475: Bernese diplomats arrived in Sion requesting aid from the bishop and the Seven Zenden. A treaty of mutual defense was immediately signed so Bernese forces could launch an invasion of Vaud, while the combined armies of Walter and the Seven Zenden could attack Lower Valais.
The seven Zenden on the eve of the Burgundian Wars, 1470.
The seven Zenden on the eve of the Burgundian Wars, 1470. Wikimedia
In response to the Valaisan invasion of Lower Valais, Yolande dispatched her brother-in-law, John-Louis of Savoy, the archbishop of Geneva, to vanquish the Sédunoise and the Seven Zenden. The joint armies of Walter and the Seven Zenden launched two unsuccessful attempts to take the town of Conthey, managing only to come away with some looted wheat. On November 12, the main Savoyard army arrived in Conthey. Historians estimate that this impressive contingent numbered around 10,000 men and included 1,500 noble cavalry officers. The Sédunoise and the Seven Zenden were outnumbered. Only 300 men – including sixty skilled pikemen from Bern and the Three Leagues of Graubünden – were available to defend Sion. Around 4,000 militia men from the Seven Zenden and some 3,000 volunteers from Bern, Solothurn, and Fribourg marched in the direction of Sion, but the Sédunoise were unsure if they would arrive in time. The situation in Sion appeared hopeless; the Savoyards had every expectation of taking Sion with ease the next day.
Sion around 1588. Panorama in the Cosmographia by Sebastian Münster.
Sion around 1588. Panorama in the Cosmographia by Sebastian Münster. notrehistoire.ch

The Battle on the Planta

The Battle on the Planta commenced on the morning of November 13. After the Savoyard army crossed the Morge de Conthey River, they successfully routed the advance guard of the Sédunoise, pushing them back toward Sion. A smaller battalion of Savoyard troops had already moved in the direction of Savièse. They sacked Savièse, as well as the villages of Malerna and Zuschuat, with the aim to not only terrorize civilians but to encircle Sion. As the main Savoyard army began to storm the westernmost parts of Sion, the militias of the Seven Zenden arrived in the city. They pushed the Savoyards back to La Planta, located just outside of Sion's citywalls. As the Seven Zenden’s militias were lightly equipped and exhausted from their march, they could not challenge the Savoyards on the field of open battle. In their moment of need, Swiss forces, under Bernese leadership and with the help of troops from Fribourg and Solothurn, crossed the Sanetsch Pass and appeared on the horizon. Surprised by the arrival of Swiss forces, the Savoyard battalion retreated to the west, while the Swiss amassed outside the gates of Sion. The Séduonois, Seven Zenden, and the Swiss fought the larger Savoyard army in bloody hand-to-hand combat as a united force. Despite their smaller numbers, the rapid advance of the allies and their ferocity in battle provoked a panic among the Savoyard soldiers – they fled en masse, leaving behind a rich booty of armor, weaponry, horses, and richly-embroidered banners. Savoy's losses at the Battle on the Planta were heavy: Over 1,000 died, including some 300 noblemen. By contrast, the allied forces took many prisoners and suffered minor losses.
In hand-to-hand combat, the Confederate troops slew over three hundred Savoyards at the gates of Sion, 1475.
In hand-to-hand combat, the Confederate troops slew over three hundred Savoyards at the gates of Sion, 1475. Burgerbibliothek Bern
Capitalizing on the success of the Battle on the Planta, Walter’s armies pursued the retreating Savoyards and seized Savoyard-controlled Lower Valais as far as Saint-Maurice. Seventeen fortified castles in total were taken, and the Swiss and Valaisans subsequently destroyed or dismantled many of these. The Swiss brokered a truce with Yolande in early December 1475, and Bern and Fribourg garrisoned the towns of Conthey and Saint-Maurice as a precautionary measure to dissuade Savoy against hostile retaliatory measures. Confederate support of the bishop of Sion and the Seven Zenden was indispensable in securing the victory at the Battle on the Planta, and the relationship between Valais and the Swiss Confederation blossomed over the next century. Walter, for his part, firmly believed that the victory over Savoy was procured through the divine intervention of the Virgin Mary, St. Catherine, and St. Théodule. Valaisans therefore celebrated the festival of Notre-Dame des Sept-Joies on November 13th, until 1914.

…know that we will not forget it. We announce this to you in the hope that you will rejoice greatly with us in our good fortune as we do with you.

Walter, Bishop of Sion in a letter of gratitude to Confederate leaders in Bern, composed on the evening of 13 November, 1475
Conthey in a hand drawing from 1868.
Conthey, occupied by the Swiss after the Battle of the Planta, in a hand drawing from 1868. In the foreground, the ruins of the castle of the Counts of Savoy, destroyed in 1475. Swiss National Museum
The Valaisan occupation of the Great St. Bernard Pass proved disastrous to Burgundy and its allies as mercenaries from Milan could not participate in the forthcoming battles against the Swiss. One may thus count the Battle on the Planta as one in an important series of disasters that contributed to Burgundy's demise. Following the death and defeat of Charles “the Bold” by the Swiss at the Battle of Nancy, Walter arranged a special diet to be held between the Sédunoise and the Seven Zenden at Christmas 1477 in Sion. It was then and there to annex Lower Valais officially. The new territories became subject to the Seven Zenden with common rule lasting until 1792. Savoy refused to recognize the annexation until 1528, and the duchy never recovered these lands. Cut off from the lucrative alpine passes to Italy and surrounded by avaricious enemies, Savoy entered into a period of marked decline that would last until the end of the Italian Wars in 1559. The military success won at the Battle on the Planta set the stage for future Valaisan expansion against Milan in the decades that followed, and historians recognize the battle as one of the most important events in Valaisan history.

Published on: 10.11.2022

URL: https://blog.nationalmuseum.ch/en/2022/11/the-battle-on-the-planta-1475/

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