THE war of Upper Peru was in fact a frontier war, although it took the Argentines nine years to realise the fact. But San Martín clearly grasped it from the time of his brief command of the northern army in 1814. In April of that year he wrote to a friend, 'Here is my secret: a small well-disciplined army in Mendoza to pass to Chile and finish off the "goths" there, supporting a government of firm friends in order to end the anarchy there. Uniting our forces, we shall pass by sea to take Lima. That is the road, and not this: until we have Lima, the war cannot end'. His plan was secret: for if divulged it would have stamped him as a madman and left him powerless from the beginning. During three years of patient effort he pursued this plan almost independently, educating and convincing his contemporaries, politicians and generals alike, by means of action and of facts.
This daring design of leading an army away from the Argentine plains, over the towering rampart of the Andes, at the very time when the royalists were constantly threatening and attempting invasion from Upper Peru, would have been impossible but for the persistent defence of the northern frontier by Güemes. San Martín fully realised this and cordially avowed his reliance upon ' Güemes and his valiant gauchos'.
San Martín's first step was the apparently modest request for a civil post as Governor-Intendant of the Province of Cuyo, comprising the jurisdictions of Mendoza, San Juan and San Luis; that is to say the region originally settled from Chile, then trans-