In the early morning hours, forces commanded by Charles Emmanuel I, the Duke of Savoy, and his brother-in-law, Philip III of Spain, attempted to seize Geneva through a surprise assault. The city, fortified by a combination of local militia and enthusiastic citizens, quickly mobilized to confront this attack. The Duke's ambitions to expand his territory into Geneva met fierce opposition as the locals, fueled by a strong sense of identity and independence, engaged the invaders in intense urban combat. Key figures among the citizen defenders included local leaders and militia captains who inspired their fellow citizens to protect their home against external aggression. The fierce urban battle highlighted the commitment of the Genevese to their societal values and political autonomy.

As the conflict waxed and waned, the determined defense tactics employed by the citizens foiled the invaders' plans. Ultimately, after intense fighting, the Savoyard and Spanish forces were forced to retreat, suffering considerable losses. This victory was a watershed moment for Geneva, affirming the city's independence and determination to resist foreign domination. Consequently, the event is commemorated each year during the Fête de l'Escalade, which celebrates the historical solidarity and successful defense of the city.

In the aftermath, Geneva fortified its defenses and strengthened its political structures, which contributed to its long-term stability. The successful repulsion of the attack not only boosted morale among the citizens but also served as a critical reminder of their ability to stand against more powerful adversaries.