Battle of Buenos Aires

British columns marched at dawn into the grid of narrow streets, and the city turned its flat rooftops into a killing ground, pouring musket fire, grenades and boiling water down onto the trapped soldiers. Within two days an army that had already taken Montevideo was broken, and its general surrendered and agreed to leave the whole region, later to be court-martialled and disgraced at home. The defence was led not by Spain's regular army but by locally raised militia and armed citizens, including a corps of enslaved and free Black men. It was the second failed British attempt in two years. Having saved themselves with almost no help from Madrid, the people of Buenos Aires drew a lasting lesson in self-reliance, a direct prelude to the revolution of 1810.

The two British defeats of 1806 and 1807 are widely read as a hinge in the political consciousness of the River Plate: the criollos discovered that they could arm, organize and govern their own defence without the crown, and the militias raised in those years became the armed and political core that acted in the May Revolution of 1810. The debate is over how directly the defence fed independence sentiment, against how much later nationalist writers built it up in hindsight. A quieter question is the erasure of the enslaved and free Black defenders from the popular memory of the victory. The episode is remembered in Argentina as the Reconquista and the Defensa.