In fact he had been present both at the burning of Washington and the British defeat at New Orleans in 1815. After the war, Miller had rejected the idea of moving into the unexciting world of trade and had travelled to the River Plate where, in 1817 at the age of 22, he had been commissioned as a captain in the Buenos Aires Artillery. Posted to the Army of the Andes, he arrived too late to be present at Chacabuco, but during the debacle of Cancha Rayada had shown the first sign of his astonishing bravery by saving abattery of guns inthe face ofthe enemy. San Martin had been so impressed by his performance that he promptly made him an aide-de-camp. It was the first achievement in a career that was to culminate in Miller’s appointment as a Peruvian General.
Chacabuco and Maipú may havedealt shattering blows to the Spanish army’s position in Chile, but the Spanish navy stillcommandedthe Pacific. But this was due as much to patriot inaction as to the number of ships at its disposal. Indeed, the Napoleonic Wars had crippled Spain’s once proud Navy, and the French occupation had destroyed the logistical base of itsdockyards. There was therefore a woeful shortage of ships to counter the rebellion in South America. Commodore Bowles reported at the end of 1817, that ‘the whole naval force of His Catholic Majesty in these seas consists of the Venganza and Esmeraldaof 36 guns each, and three corvettes of 16 or 18 guns.’In fact, Spain also had a dozen small gunboats and armed ships in the area, but these were of little military use except for port defence. In1817, the Spanish Government estimated that it needed 20 ships of the line, 30 frigates and 40 lesser crafttomeet itsglobal commitments.