On 11 July 1302 the so-called ‘Battle of the Golden Spurs’ wasfought at Courtrai between French knights and Flemish foot soldiers. Itwas one of the many battles in the war between Guy of Dampierre,Count of Flanders, and Philip the Fair, King of France. Although thisbattle was not inspired by feelings of national identity, the date (11 July)was chosen in 1973 as the national feast-day of the Flemings.In this article we try to explain how the unexpected victory of theFlemish soldiers gave birth to a feeling of collective Flemish pride thathad its influence on the perception of the facts and eventually on medievalhistoriography. Through the process of ‘invention of tradition’ the‘Battle of the Golden Spurs’ became the symbol of Flemish resistanceagainst the French occupant. This is why Flanders still commemoratesthe 11th of July, not because of what really happened, but because ofwhat historians thought that had happened.