> Confidence and determination and unusual resources also made it possible for groups of commoners to assert themselves during the post-plague period. In the 1300s, the Flemish cities organized themselves as disciplined forces and defeated noble-led armies. Bruges, for instance, had several advantages: it was a populous, rich trading city that could afford to resist the traditional ruling class if the right circumstances occurred; and indeed many citizens were willing to put their lives on the line to achieve their own vision of self-government. The townsmen of Flanders even adopted a scary and non-standard weapon, the goedendag – a combination of a short spear and long club. These commoners (many of whom by this time were more prosperous than earlier generations) had distinctive weaponry and a tactical protocol which made them an effective military and political factor.
This refers to the 1302 Battle of the Golden Spurs where an army of footmen prevailed over a French army of knights. That victory was re-appropriated and romanticized in the 19th century as part of the national mythology of the young Belgian nation.
The reality is far more complex and less rosy then how it is put here by the author.
14th century Flanders saw several uprising and rebellions. The count was also a feudal vazal to the French Crown. As such, the King sent several armies to appease the unruly county between 1302 and 1400, each time crushing those same footmen. Mons-en-Pévele, Roosebeke, Cassel are less known names for good reasons.
As far as the French Crown was concerned, the county of Flanders and it's cities were a strategic pawn in a larger European feudal realm dominated by the conflict with England (Hundred's Years War). The wealth of the cities themselves came from the wool trade with England, and the trade with Southern Europe, later on, in particular, with Lombardy. For instance, the French Crown revoking trade with England was a direct cause of the Artevelde rebellion in 1339.
Moreover, the cities themselves were semi-autonomous, held their own local political and economical interests, and were very much feuding with each other, or their liege lord, the Count of Flanders to preserve their own local autonomy, expand their economic interests and the ability to trade without getting excessively taxed by established feudal elites. In reality, those "disciplined forces" were militia's and warbands which were held together by tenuous alliances when facing the French Army; and would openly fight each other when push comes to shove. The Battle of Beverhoutsveld saw the cities of Bruges and Ghent facing each other off, whereas just 40 years prior, those same cities were allies in that same Artevelde rebellion against the French Crown. [1]
[1] https://en.wikipedia.org/wiki/Battle_of_Beverhoutsveld
The wealth and political power was truly concentrated with the city's patrician elites whereas the majority of citizens were illiterate menial workers with little say in governance of their city. They lived in precarious circumstances and any awareness of the wider political context was limited to their own personal social and economic situation. At best, they would support popular leaders who's interests were perceived as aligned with theirs. While Jacob van Artevelde was seen as a popular hero, he very much belonged to a wealthy urban economic elite who had, equally, every interest to reinstate the English wool trade.
Finally, the Plague happened in the 1350's. Those same Flemish cities were already quite powerful in the late 13th century.
And all of that is just barely scratching the surface of the historical complexity which gets skimped in this article. It's never a good idea to single sidedly focus on the military aspect and try to explain history from that point of view.