After Corunna, Soult turned his attention to the invasion of Portugal. Discounting garrisons and the sick, Soult's II Corps had 20,000 men for the operation. He stormed the Spanish naval base at Ferrol on 26 January 1809, capturing eight ships of the line, three frigates, several thousand prisoners and 20,000 Brown Bess muskets, which were used to re-equip the French infantry. In March 1809, Soult invaded Portugal through the northern corridor, with Francisco da Silveira's 12,000 Portuguese troops unraveling amid riot and disorder, and within two days of crossing the border Soult had taken the fortress of Chaves. Swinging west, 16,000 of Soult's professional troops attacked and killed 4,000 of 25,000 unprepared and undisciplined Portuguese at Braga at the cost of 200 Frenchmen. In the First Battle of Porto on 29 March, the Portuguese defenders panicked and lost between 6,000 and 20,000 men dead, wounded or captured and immense quantities of supplies. Suffering fewer than 500 casualties Soult had secured Portugal's second city with its valuable dockyards and arsenals intact. Soult halted at Porto to refit his army before advancing on Lisbon.