At the Somosierra mountain pass, 60 miles north of Madrid, a heavily outnumbered Spanish detachment of conscripts and artillery under Benito de San Juan aimed to block Napoleon's advance on the Spanish capital. Napoleon overwhelmed the Spanish positions in a combined arms attack, charging the Polish Chevau-légers of the Imperial Guard at the Spanish guns while French infantry advanced up the slopes. The victory removed the last obstacle barring the road to Madrid, which fell several days later.